Organic light-emitting device

ABSTRACT

An organic light-emitting device includes: a first electrode; a second electrode facing the first electrode; an emission layer between the first electrode and the second electrode; a hole transport region between the first electrode and the emission layer; and an electron transport region between the emission layer and the second electrode, wherein the electron transport region includes a first compound, at least one selected from the hole transport region and the electron transport region includes a second compound, the first compound is represented by one selected from Formulae 1A to 1D, and the second compound is represented by Formula 2A or Formula 2B:

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2015-0184083, filed on Dec. 22, 2015, in the Korean Intellectual Property Office, the entire content of which is incorporated herein by reference.

BACKGROUND 1. Field

One or more aspects of embodiments of the present disclosure relate to an organic light-emitting device.

2. Description of the Related Art

Organic light-emitting devices are self-emission devices that have wide viewing angles, high contrast ratios, short response times, and excellent brightness, driving voltage, and response speed characteristics, and can produce full-color images.

The organic light-emitting device may include a first electrode disposed (e.g., positioned) on a substrate, and a hole transport region, an emission layer, an electron transport region, and a second electrode, which are sequentially disposed on the first electrode. Holes provided from, for example, the first electrode may move toward the emission layer through the hole transport region, and electrons provided from, for example, the second electrode may move toward the emission layer through the electron transport region. Carriers, such as holes and electrons, may then recombine in the emission layer to produce excitons. These excitons transition from an excited state to a ground state, thereby generating light.

SUMMARY

One or more aspects of embodiments of the present disclosure are directed towards an organic light-emitting device having a low driving voltage and high efficiency.

Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments.

According to one or more embodiments, an organic light-emitting includes:

a first electrode;

a second electrode facing the first electrode;

an emission layer between the first electrode and the second electrode;

a hole transport region between the first electrode and the emission layer; and

an electron transport region between the emission layer and the second electrode,

wherein the electron transport region includes a first compound,

at least one selected from the hole transport region and the electron transport region includes a second compound,

the first compound is represented by one selected from Formulae 1A to 1 D, and

the second compound is represented by Formula 2A or 2B:

In Formulae 1A to 1D, 2A, and 2B,

ring A₁ may be a C₅-C₆₀ carbocyclic group or a C₁-C₃₀ heterocyclic group, each substituted with at least one *-[(L₁₁)_(a11)-(R₁₁)_(b11)], and ring A₂ may be a C₅-C₆₀ carbocyclic group or a C₁-C₃₀ heterocyclic group, each substituted with at least one *-[(L₁₂)_(a12)-(R₁₂)_(b12)].

rings A₂₁, A₂₂, and A₂₃ may each independently be a C₅-C₆₀ carbocyclic group or a C₁-C₃₀ heterocyclic group, each substituted with at least one *-[(L₂₂)_(a22)-(R₂₂)_(b22)],

T₁ to T₄ may each independently be carbon or nitrogen, a bond between T₁ and T₂ may be a single bond, and a bond between T₃ and T₄ may be a double bond,

T₁₁ and T₁₂ may each independently be carbon or nitrogen, two or more selected from three T₁₁(s) in Formula 2A may be identical to or different from each other, T₁₃ may be N or C(R₂₇), T₁₄ may be N or C(R₂₈), two or more selected from three T₁₂(s) in Formula 2A may be identical to or different from each other, two T₁₁(s) in Formula 2B may be identical to or different from each other, two T₁₂(s) in Formula 2B may be identical to or different from each other, a bond between T₁₁ and T₁₂ may be a single bond or a double bond, a case where three T₁₁(s) and three T₁₂(s) in Formula 2A are all nitrogen may be excluded, and a case where two T₁₁(s), two T₁₂(s), T₁₃, and T₁₄ in Formula 2B are all nitrogen may be excluded,

ring A₁ may be condensed with a 5-membered ring in Formulae 1B and 1D, while sharing T₁ and T₂ therewith, and ring A₂ may be condensed with a 5-membered ring in Formulae 1C and 1D, while sharing T₃ and T₄ therewith,

rings A₂₁, A₂₂, and A₂₃ may each be condensed with a 7-membered ring in Formulae 2A and 2B, while sharing T₁₁ and T₁₂ therewith,

X₁ may be selected from O, S, and N-[(L₁)_(a1)-(R₁)_(b1)],

X₂ may be N or C-(L₂)_(a2)-(R₂)_(b2), X₃ may be N or C-(L₃)_(a3)-(R₃)_(b3), X₄ may be N or C-(L₄)_(a4)-(R₄)_(b4), and X₅ may be N or C-(L₅)_(a5)-(R₅)_(c5),

X₂₁ may be selected from O, S, Se, C(R₂₃)(R₂₄), Si(R₂₃)(R₂₄), and N-[(L₂₁)_(a21)-(R₂₁)_(b21)],

L₁ to L₅, L₁₁, L₁₂, L₂₁, and L₂₂ may each independently be selected from a substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀ arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

a1 to a5, a11, a12, a21, and a22 may each independently be an integer selected from 0 to 5,

R₁ to R₅, R₁₁, R₁₂, R₂₁ to R₂₄, R₂₇, and R₂₈ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂),

b1 to b5, b11, b12, b21, and b22 may each independently be an integer selected from 0 to 4,

R₄ and R₅ may be optionally connected to each other to form a saturated or unsaturated ring,

at least one substituent of the substituted C₃-C₁₀ cycloalkylene group, the substituted C₁-C₁₀ heterocycloalkylene group, the substituted C₃-C₁₀ cycloalkenylene group, the substituted C₁-C₁₀ heterocycloalkenylene group, the substituted C₆-C₆₀ arylene group, the substituted C₁-C₆₀ heteroarylene group, the substituted divalent non-aromatic condensed polycyclic group, the substituted divalent non-aromatic condensed heteropolycyclic group, the substituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group may be selected from the group consisting of:

deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂);

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, and a terphenyl group;

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group; and

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryl group substituted with a C₁-C₆₀ alkyl group, a C₆-C₆₀ aryl group substituted with a C₆-C₆₀ aryl group, a terphenyl group, a C₁-C₆₀ heteroaryl group, a C₁-C₆₀ heteroaryl group substituted with a C₁-C₆₀ alkyl group, a C₁-C₆₀ heteroaryl group substituted with a C₆-C₆₀ aryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readily appreciated from the following description of the example embodiments, taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic view of organic light-emitting device according to an embodiment;

FIG. 2 is a schematic view of organic light-emitting device according to another embodiment;

FIG. 3 is a schematic view of organic light-emitting device according to another embodiment;

FIG. 4 is a schematic view of organic light-emitting device according to another embodiment;

FIG. 5 is a schematic view of organic light-emitting device according to another embodiment;

FIG. 6 is a schematic view of organic light-emitting device according to another embodiment.

DETAILED DESCRIPTION

In the following detailed description, only certain embodiments of the present disclosure are shown and described, by way of illustration. As those skilled in the art would recognize, the present disclosure may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein.

An organic light-emitting device according to an embodiment may include a first electrode, a second electrode facing the first electrode, an emission layer between the first electrode and the second electrode, a hole transport region between the first electrode and the emission layer, and an electron transport region between the emission layer and the second electrode, wherein the electron transport region may include a first compound and at least one selected from the hole transport region and the electron transport region may include a second compound.

The first compound may be represented by one selected from Formulae 1A to 1D, and the second compound may be represented by Formula 2A or 2B:

In Formulae 1B to 1D, ring A₁ may be a C₅-C₆₀ carbocyclic group or a C₁-C₃₀ heterocyclic group, each substituted with at least one *-[(L₁₁)_(a11)-(R₁₁)_(b11)], and ring A₂ may be a C₅-C₆₀ carbocyclic group or a C₁-C₃₀ heterocyclic group, each substituted with at least one *-[(L₁₂)_(a12)-(R₁₂)_(b12)]. Descriptions of L₁₁, L₁₂, a11, a12, R₁₁, R₁₂, b11, and b12 are the same as described below.

T₁ to T₄ may each independently be carbon or nitrogen; a bond between T₁ and T₂ may be a single bond; a bond between T₃ and T₄ may be a double bond; ring A₁ may be condensed (e.g., fused) with a 5-membered ring in Formulae 1B and 1D, while sharing T₁ and T₂ therewith; and ring A₂ may be condensed (e.g., fused) with a 5-membered ring in Formulae 1C and 1D, while sharing T₃ and T₄ therewith.

For example, ring A₁ in Formulae 1B to 1D may be selected from a cyclopentadiene group, a dihydropyridine group, a dihydropyrazine group, a dihydroquinoline group, a dihydroisoquinoline group, a benzotetrahydropyran group, a benzotetrahydrothiopyran group, a tetrahydronaphthalene group, an imidazolodihydroquinoline group, an imidazolodihydronaphthalene group, a pyrrolodihydronaphthalene group, and a dihydrophenanthrene group, each substituted with at least one *-[(L₁₁)_(a11)-(R₁₁)_(m1)],

ring A₂ may be selected from a benzene group, a naphthalene group, an anthracene group, an indene group, a fluorene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a quinoline group, an isoquinoline group, a pyrrole group, a pyrazole group, an imidazole group, an oxazole group, a thiazole group, a cyclopentadiene group, a silole group, a selenophene group, a furan group, a thiophene group, an indole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, an indene group, a benzosilole group, a benzoselenophene group, a benzofuran group, a benzothiophene group, a carbazole group, a fluorene group, a dibenzosilole group, a dibenzoselenophene group, a dibenzofuran group, a dibenzothiophene group, a pyrrolopyridine group, a cyclopentapyridine group, a silolopyridine group, a selenophenopyridine group, a furopyridine group, a thienopyridine group, a pyrrolopyrimidine group, a cyclopentapyrimidine group, a cyclopyrimidine group, a selenophenopyrimidine group, a furopyrimidine group, a thienopyrimidine group, a pyrrolopyrazine group, a cyclopentapyrazine group, a silolopyrazine group, a selenophenopyrazine group, a furopyrazine group, a thienopyrazine group, a pyrrolonaphthalene group, a cyclopentanaphthalene group, a silolonaphthalene group, a selenophenonaphthalene group, a furonaphthalene group, a thienonaphthalene group, a pyrroloquinoline group, a cyclopentaquinoline group, a siloloquinoline group, a selenophenoquinoline group, a furoquinoline group, a thienoquinoline group, a pyrroloisoquinoline group, a cyclopentaisoquinoline group, a siloloisoquinoline group, a selenophenoisoquinoline group, a furoisoquinoline group, a thienoisoquinoline group, an azacarbazole group, an azafluorene group, an azadibenzosilole group, an azadibenzoselenophene group, an azadibenzofuran group, an azadibenzothiophene group, an indenoquinoline group, an indenoisoquinoline group, an indenoquinoxaline group, a phenanthroline group, and an indolonaphthalene group, each substituted with at least one *-[(L₁₂)_(a12)-(R₁₂)_(b12)].

In various embodiments, ring A₁ in Formulae 1B to 1D may be selected from groups represented by Formulae 1-1 to 1-8, each substituted with at least one *-[(L₁₁)_(a11)-(R₁₁)_(b11)], and ring A₂ may be selected from groups represented by Formulae 1-9 to 1-21, each substituted with at least one *-[(L₁₂)_(a12)-(R₁₂)_(b12)]:

wherein, in Formulae 1-1 to 1-21,

descriptions of T₁ to T₄ are the same as described herein,

X₁₁ and X₁₂ may each independently be O or S, or may each independently be a moiety including C, and

T₃₁ to T₃₈ and T₄₁ to T₄₈ may each independently be N or C, or may each independently be a moiety including C.

For example, in Formulae 1-1 to 1-21, X₁₁ may be O, S, or C(R₁₃)(R₁₄), X₁₂ may be O, S, or C(R₁₅)(R₁₆), T₃₁ to T₃₈ may each independently be N, C, or C-[(L₁₁)_(a11)-(R₁₁)_(b11)] and T₄₁ to T₄₈ may each independently be N or C-[(L₁₂)_(a11)-(R₁₂)_(b12)]. R₁₃ to R₁₆ may each independently be selected from groups represented by *-[(L₁₁)_(a11)-(R₁₁)_(b11)] as described herein.

In various embodiments, in Formulae 1B to 1D, ring A₁ may be selected from groups represented by Formulae 1-31 to 1-41, and ring A₂ may be selected from groups represented by Formulae 1-51 to 1-64:

wherein, in Formulae 1-31 to 1-41 and 1-51 to 1-64,

descriptions of T₁ to T₄ are the same as described herein,

X₁₁ may be O, S, or C(R₁₃)(R₁₄),

X₁₂ may be O, S, or C(R₁₅)(R₁₆), and

R₄₁ to R₄₈ may each independently be selected from substituents represented by *-[(L₁₁)_(a11)-(R₁₁)_(b11)] as described herein, and R₅₁ to R₅₈ may each independently be selected from substituents represented by *-[(L₁₂)_(a12)-(R₁₂)_(b12)] as described herein. R₁₃ to R₁₆ may each independently be selected from groups represented by *-[(L₁₁)_(a11)-(R₁₁)_(b11)] as described herein.

Rings A₂₁, A₂₂, and A₂₃ in Formulae 2A and 2B may each independently be a C₅-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group, each substituted with at least one *-[(L₂₂)_(a22)-(R₂₂)_(b22)]. L₂₂, a22, R₂₂, and b22 are the same as described below.

T₁₁ and T₁₂ in Formulae 2A and 2B may each independently be carbon or nitrogen; two or more selected from three T₁₁(s) in Formula 2A may be identical to or different from each other; T₁₃ may be N or C(R₂₇); T₁₄ may be N or C(R₂₈); two or more selected from three T₁₂(s) in Formula 2A may be identical to or different from each other; two T₁₁(s) in Formula 2B may be identical to or different from each other; two T₁₂ (s) in Formula 2B may be identical to or different from each other; a bond between T₁₁ and T₁₂ may be a single bond or a double bond; a case where three T₁₁(s) and three T₁₂(s) in Formula 2A are all nitrogen may be excluded; a case where two T₁₁(s), two T₁₂(s), T₁₃, and T₁₄ in Formula 2B are all nitrogen may be excluded; and rings A₂₁, A₂₂, and A₂₃ may each be condensed (e.g., fused) with a 7-membered ring in Formulae 2A and 2B, while sharing T₁₁ and T₁₂ therewith.

*-[(L₂₂)_(a22)-(R₂₂)_(b22)] substituent in ring A₂₁, *-[(L₂₂)_(a22)-(R₂₂)_(b22)] substituent in ring A₂₂, and *-[(L₂₂)_(a22)-(R₂₂)_(b22)] substituent in ring A₂₃ may be identical to or different from one another.

In addition, when the number of *-[(L₂₂)_(a22-)(R₂₂)_(b22)] substituents in ring A₂₁ is two or more, two or more *-[(L₂₂)_(a22)-(R₂₂)_(b22)](s) may be identical to or different from each other; when the number of *-[(L₂₂)_(a22)-(R₂₂)_(b22)] substituents in ring A₂₂ is two or more, two or more *-[(L₂₂)_(a22)-(R₂₂)_(b22)1](s) may be identical to or different from each other; and when the number of *-[(L₂₂)_(a22)-(R₂₂)_(b22)] substituents in ring A₂₃ is two or more, two or more *-[(L₂₂)_(a22)-(R₂₂)_(b22)](s) may be identical to or different from each other.

In various embodiments, rings A₂₁, A₂₂, and A₂₃ in Formulae 2A and 2B may each independently be selected from a benzene group, a naphthalene group, an anthracene group, an indene group, a fluorene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a quinoline group, an isoquinoline group, a pyrrole group, a pyrazole group, an imidazole group, an oxazole group, a thiazole group, a cyclopentadiene group, a silole group, a selenophene group, a furan group, a thiophene group, an indole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, an indene group, a benzosilole group, a benzoselenophene group, a benzofuran group, a benzothiophene group, a carbazole group, a fluorene group, a dibenzosilole group, a dibenzoselenophene group, a dibenzofuran group, a dibenzothiophene group, a pyrrolopyridine group, a cyclopentapyridine group, a silolopyridine group, a selenophenopyridine group, a furopyridine group, a thienopyridine group, a pyrrolopyrimidine group, a cyclopentapyrimidine group, a silolopyrimidine group, a selenophenopyrimidine group, a furopyrimidine group, a thienopyrimidine group, a pyrrolopyrazine group, a cyclopentapyrazine group, a silolopyrazine group, a selenophenopyrazine group, a furopyrazine group, a thienopyrazine group, a pyrrolonaphthalene group, a cyclopentanaphthalene group, a silolonaphthalene group, a selenophenonaphthalene group, a furonaphthalene group, a thienonaphthalene group, a pyrroloquinoline group, a cyclopentaquinoline group, a siloloquinoline group, a selenophenoquinoline group, a furoquinoline group, a thienoquinoline group, a pyrroloisoquinoline group, a cyclopentaisoquinoline group, a siloloisoquinoline group, a selenopheno isoquinoline group, a furoisoquinoline group, a thienoisoquinoline group, an azacarbazole group, an azafluorene group, an azadibenzosilole group, an azadibenzoselenophene group, an azadibenzofuran group, an azadibenzothiophene group, an indenoquinoline group, an indenoisoquinoline group, an indenoquinoxaline group, a phenanthroline group, and an indolonaphthalene group, each substituted with at least one *-[(L₂₂)_(a22)-(R₂₂)_(b22)].

In various embodiments, in the second compound represented by Formulae 2A and 2B, a case where rings A₂₁, A₂₂, and A₂₃ are all a benzene group substituted with at least one *-[(L₂₂)_(a22)-(R₂₂)_(b22)] may be excluded.

In various embodiments, rings A₂₁, A₂₂, and A₂₃ in Formulae 2A and 2B may each independently be selected from groups represented by Formulae 2-1 to 2-36, each substituted with at least one *-[(L₂₂)_(a22)-(R₂₂)_(b22)]:

wherein, in Formulae 2-1 to 2-36,

descriptions of T₁₁ and T₁₂ are the same as described herein,

X₂₂ and X₂₃ may each independently be O, S, or Se, or may each independently be a moiety including C, N, or Si, and

T₂₁ to T₂₈ may each independently be N, or may each independently be a moiety including C.

For example, in Formulae 2-1 to 2-36, X₂₂ and X₂₃ may each independently be O, S, Se, C(R₂₅)(R₂₆), N-[(L₂₂)_(a22)-(R₂₂)_(b22)], or Si(R₂₅)(R₂₆); and T₂₁ to T₂₈ may each independently be N or C-[(L₂₂)_(a22)-(R₂₂)_(b22)]. R₂₅, R₂₆, and R₃₀ may each independently be selected from groups represented by *-[(L₂₂)_(a22)-(R₂₂)_(b22))] as described herein.

In various embodiments, rings A₂₁, A₂₂, and A₂₃ in Formulae 2A and 2B may each independently be selected from groups represented by Formulae 2-101 to 2-229:

wherein, in Formulae 2-101 to 2-229,

descriptions of T₁₁ and T₁₂ are the same as described herein,

X₂₂ and X₂₃ may each independently be O, S or Se, or may each independently be a moiety including C, N, or Si, and

R₃₁ to R₃₈ may each independently be selected from substituents represented by *-[(L₂₂)_(a22-)(R₂₂)_(b22)] as described herein.

In various embodiments, the second compound may be represented by Formula 2A, wherein rings A₂₁, A₂₂, and A₂₃ may be selected from Formulae 2-1 to 2-36 and arranged as shown in Table 1 (the second compounds respectively corresponding to each arrangement of rings A₂₁, A₂₂, and A₂₃ shown in Table 1 are denoted as Formulae 2-201A to 2-269A).

TABLE 1 Formula No. Formula No. Formula No. Formula No. of ring A₂₁ of ring A₂₂ of ring A₂₃ 2-201A 2-2 2-4 2-4 2-202A 2-4 2-4 2-1 2-203A 2-4 2-4 2-2 2-204A 2-4 2-4 2-3 2-205A 2-4 2-1 2-4 2-206A 2-4 2-2 2-4 2-207A 2-4 2-4 2-10 2-208A 2-11 2-4 2-4 2-209A 2-4 2-4 2-11 2-210A 2-4 2-10 2-4 2-211A 2-4 2-4 2-8 2-212A 2-4 2-9 2-4 2-213A 2-4 2-4 2-14 2-214A 2-17 2-4 2-4 2-215A 2-4 2-4 2-15 2-216A 2-13 2-4 2-4 2-217A 2-4 2-4 2-16 2-218A 2-4 2-4 2-13 2-219A 2-16 2-4 2-4 2-220A 2-4 2-4 2-12 2-221A 2-4 2-4 2-17 2-222A 2-4 2-16 2-4 2-223A 2-4 2-15 2-4 2-224A 2-4 2-14 2-4 2-225A 2-4 2-17 2-4 2-226A 2-19 2-4 2-4 2-227A 2-22 2-4 2-4 2-228A 2-18 2-4 2-4 2-229A 2-23 2-4 2-4 2-230A 2-21 2-4 2-4 2-231A 2-20 2-4 2-4 2-232A 2-4 2-23 2-4 2-233A 2-4 2-18 2-4 2-234A 2-4 2-21 2-4 2-235A 2-4 2-19 2-4 2-236A 2-5 2-2 2-4 2-237A 2-5 2-1 2-4 2-238A 2-2 2-2 2-4 2-239A 2-4 2-23 2-1 2-240A 2-6 2-10 2-4 2-241A 2-4 2-4 2-29 2-242A 2-7 2-4 2-10 2-243A 2-11 2-4 2-10 2-244A 2-4 2-10 2-6 2-245A 2-11 2-11 2-4 2-246A 2-11 2-11 2-5 2-247A 2-11 2-11 2-10 2-248A 2-7 2-9 2-4 2-249A 2-4 2-4 2-25 2-250A 2-11 2-15 2-4 2-251A 2-18 2-28 2-4 2-252A 2-23 2-10 2-4 2-253A 2-4 2-27 2-4 2-254A 2-6 2-18 2-4 2-255A 2-4 2-23 2-5 2-256A 2-23 2-4 2-14 2-257A 2-17 2-4 2-14 2-258A 2-14 2-4 2-12 2-259A 2-17 2-4 2-12 2-260A 2-14 2-16 2-2 2-261A 2-17 2-5 2-14 2-262A 2-17 2-13 2-17 2-263A 2-17 2-14 2-12 2-264A 2-17 2-12 2-12 2-265A 2-5 2-1 2-18 2-266A 2-4 2-29 2-4 2-267A 2-4 2-31 2-4 2-268A 2-4 2-33 2-4 2-269A 2-4 2-35 2-4

In various embodiments, the second compound may be represented by Formula 2B, wherein rings A₂₁ and A₂₃ may be selected from Formulae 2-1 to 2-36 and arranged as shown in Table 2 (the second compounds respectively corresponding to each arrangement of rings A₂₁ and A₂₃ shown in Table 2 are denoted as Formulae 2-201B to 2-215B).

TABLE 2 Formula No. Formula Formula No. Formula No. or ring A₂₁ No. of ring A₂₂ of ring A₂₃ 2-201B 2-4 — 2-19 2-202B 2-4 — 2-22 2-203B 2-4 — 2-18 2-204B 2-4 — 2-23 2-205B 2-4 — 2-21 2-206B 2-4 — 2-20 2-207B 2-5 — 2-23 2-208B 2-7 — 2-23 2-209B 2-4 — 2-26 2-210B 2-7 — 2-22 2-211B  2-13 — 2-16 2-212B 2-5 — 2-19 2-213B 2-7 — 2-20 2-214B  2-19 — 2-18 2-215B  2-18 — 2-18

In various embodiments, the second compound may be represented by Formula 2A, wherein rings A₂₁, A₂₂, and A₂₃ may be selected from Formulae 2-101 to 2-229 and arranged as shown in Table 3 (the second compounds respectively corresponding to each arrangement of rings A₂₁, A₂₂, and A₂₃ shown in Table 3 are denoted as Formulae 2-301A to 2-432A).

TABLE 3 Formula No. Formula No. Formula No. Formula No. of ring A₂₁ of ring A₂₂ of ring A₂₃ 2-301A 2-104 2-147 2-104 2-302A 2-102 2-104 2-104 2-303A 2-104 2-104 2-101 2-304A 2-104 2-104 2-102 2-305A 2-104 2-104 2-103 2-306A 2-104 2-101 2-104 2-307A 2-104 2-102 2-104 2-308A 2-104 2-104 2-147 2-309A 2-157 2-104 2-104 2-310A 2-104 2-104 2-157 2-311A 2-104 2-147 2-107 2-312A 2-104 2-149 2-104 2-313A 2-104 2-156 2-104 2-314A 2-107 2-147 2-106 2-315A 2-104 2-151 2-104 2-316A 2-104 2-147 2-106 2-317A 2-104 2-148 2-104 2-318A 2-104 2-150 2-104 2-319A 2-106 2-147 2-104 2-320A 2-104 2-106 2-147 2-321A 2-157 2-107 2-104 2-322A 2-106 2-104 2-147 2-323A 2-104 2-107 2-147 2-324A 2-107 2-104 2-147 2-325A 2-104 2-104 2-160 2-326A 2-104 2-111 2-157 2-327A 2-108 2-104 2-158 2-328A 2-111 2-104 2-157 2-329A 2-107 2-147 2-104 2-330A 2-104 2-104 2-135 2-331A 2-104 2-141 2-104 2-332A 2-104 2-142 2-104 2-333A 2-107 2-104 2-135 2-334A 2-104 2-111 2-135 2-335A 2-104 2-143 2-104 2-336A 2-106 2-142 2-104 2-337A 2-107 2-142 2-106 2-338A 2-104 2-104 2-169 2-339A 2-184 2-104 2-104 2-340A 2-104 2-104 2-182 2-341A 2-168 2-104 2-104 2-342A 2-104 2-104 2-183 2-343A 2-104 2-104 2-168 2-344A 2-183 2-104 2-104 2-345A 2-104 2-104 2-167 2-346A 2-104 2-104 2-184 2-347A 2-104 2-183 2-104 2-348A 2-104 2-182 2-104 2-349A 2-104 2-169 2-104 2-350A 2-104 2-184 2-104 2-351A 2-107 2-104 2-179 2-352A 2-111 2-104 2-169 2-353A 2-104 2-111 2-182 2-354A 2-106 2-104 2-185 2-355A 2-171 2-104 2-104 2-356A 2-104 2-104 2-115 2-357A 2-104 2-104 2-178 2-358A 2-104 2-106 2-167 2-359A 2-108 2-105 2-167 2-360A 2-105 2-104 2-167 2-361A 2-112 2-104 2-184 2-362A 2-104 2-192 2-104 2-363A 2-107 2-182 2-106 2-364A 2-104 2-169 2-105 2-365A 2-105 2-184 2-104 2-366A 2-105 2-169 2-105 2-367A 2-198 2-104 2-104 2-368A 2-201 2-104 2-104 2-369A 2-197 2-104 2-104 2-370A 2-202 2-104 2-104 2-371A 2-200 2-104 2-104 2-372A 2-199 2-104 2-104 2-373A 2-104 2-202 2-104 2-374A 2-104 2-197 2-104 2-375A 2-104 2-200 2-104 2-376A 2-104 2-198 2-104 2-377A 2-209 2-104 2-104 2-378A 2-207 2-104 2-104 2-379A 2-200 2-106 2-104 2-380A 2-104 2-208 2-104 2-381A 2-105 2-198 2-108 2-382A 2-202 2-102 2-104 2-383A 2-202 2-101 2-106 2-384A 2-102 2-102 2-107 2-385A 2-104 2-202 2-101 2-386A 2-123 2-147 2-104 2-387A 2-104 2-104 2-218 2-388A 2-116 2-104 2-147 2-389A 2-157 2-104 2-147 2-390A 2-107 2-147 2-115 2-391A 2-157 2-157 2-104 2-392A 2-157 2-157 2-114 2-393A 2-157 2-157 2-147 2-394A 2-116 2-147 2-104 2-395A 2-104 2-104 2-210 2-396A 2-157 2-182 2-104 2-397A 2-197 2-213 2-104 2-398A 2-202 2-167 2-104 2-399A 2-104 2-216 2-104 2-400A 2-124 2-197 2-104 2-401A 2-104 2-202 2-114 2-402A 2-168 2-104 2-169 2-403A 2-184 2-104 2-169 2-404A 2-169 2-104 2-167 2-405A 2-184 2-106 2-167 2-406A 2-169 2-183 2-102 2-407A 2-184 2-114 2-169 2-408A 2-184 2-168 2-184 2-409A 2-184 2-104 2-167 2-410A 2-184 2-167 2-167 2-411A 2-114 2-101 2-197 2-412A 2-104 2-149 2-104 2-413A 2-106 2-104 2-147 2-414A 2-104 2-104 2-168 2-415A 2-200 2-106 2-104 2-416A 2-104 2-104 2-183 2-417A 2-104 2-104 2-101 2-418A 2-105 2-169 2-105 2-419A 2-104 2-147 2-107 2-420A 2-104 2-218 2-104 2-421A 2-104 2-226 2-104 2-422A 2-104 2-222 2-104 2-423A 2-104 2-228 2-104 2-424A 2-104 2-151 2-104 2-425A 2-106 2-147 2-107 2-426A 2-104 2-147 2-106 2-427A 2-107 2-150 2-104 2-428A 2-104 2-143 2-104 2-429A 2-107 2-142 2-106 2-430A 2-104 2-142 2-104 2-431A 2-104 2-104 2-104

In various embodiments, the second compound may be represented by Formula 2B, wherein rings A₂₁ and A₂₃ may be selected from Formulae 2-101 to 2-229 and arranged as shown in Table 4 (the second compounds respectively corresponding to each arrangement of rings A₂₁ and A₂₃ shown in Table 4 are denoted as Formulae 2-301B to 2-320B).

TABLE 4 Formula No. Formula No. Formula No. Formula No. or ring A₂₁ of ring A₂₂ of ring A₂₃ 2-301B 2-104 — 2-198 2-302B 2-104 — 2-201 2-303B 2-104 — 2-197 2-304B 2-104 — 2-202 2-305B 2-104 — 2-200 2-306B 2-104 — 2-199 2-307B 2-104 — 2-203 2-308B 2-104 — 2-204 2-309B 2-106 — 2-205 2-310B 2-104 — 2-206 2-311B 2-112 — 2-199 2-312B 2-114 — 2-202 2-313B 2-116 — 2-202 2-314B 2-104 — 2-214 2-315B 2-130 — 2-201 2-316B 2-168 — 2-183 2-317B 2-114 — 2-198 2-318B 2-116 — 2-199 2-319B 2-198 — 2-197 2-320B 2-197 — 2-197

In Formulae 1A to 1D, X₁ may be selected from O, S, and N-[(L₁)_(a1)-(R₁)_(b1)], X₂ may be N or C-(L₂)_(a2)-(R₂)_(b1), X₃ may be N or C-(L₃)_(a3)-(R₃)_(b3), X₄ may be N or C-(L₄)_(a4)-(R₄)_(b4), and X₅ may be N or C-(L₅)_(a5)-(R₅)_(c5).

For example, i) in Formula 1A,

X₁ may be O, S, or N-[(L₁)_(a1)-(R₁)_(b1)], X₂ may be C-(L₂)_(a2)-(R₂)_(b2), X₃ may be N, X₄ may be C-(L₄)-(R₄)_(b4), and X₅ may be N,

X₁ may be O, S, or N-[(L₁)_(a1)-(R₁)_(b1)], X₂ may be N, X₃ may be C-(L₃)_(a3)-(R₃)_(b3), X₄ may be C-(L₄)_(a4)-(R₄)_(b4), and X₅ may be N,

X₁ may be N-[(L₁)_(a1)-(R₁)_(b1)], X₂ may be C-(L₂)_(a2)-(R₂)_(b2), X₃ may be C-(L₃)_(a3)-(R₃)_(b3), X₄ may be N, and X₅ may be N,

X₁ may be N-[(L₁)_(a1)-(R₁)_(b1)], X₂ may be N, X₃ may be C-(L₃)_(a3)-(R₃)_(b3), X₄ may be N, and X₅ may be C-(L₅)_(a5)-(R₅)_(b5),

X₁ may be N-[(L₁)_(a1)-(R₁)_(b1)], X₂ may be C-(L₂)_(a2)-(R₂)_(b2), X₃ may be C-(L₃)_(a3)-(R₃)_(b3), X₄ may be C-(L₄)_(a4)-(R₄)_(b4), and X₅ may be C-(L₅)_(a5)-(R₅)_(b5), or

X₁ may be N-[(L₁)_(a1)-(R₁)_(b1)], X₂ may be C-(L₂)_(a2)-(R₂)_(b2), X₃ may be N, X₄ may be C-(L₄)_(a4)-(R₄)_(b4), and X₅ may be C-(L₅)_(a5)-(R₅)_(b5),

ii) in Formula 1B,

T₁ may be N, T₂ may be C, X₂ may be C-(L₂)_(a2)-(R₂)_(b2), X₃ may be C-(L₃)_(a3)-(R₃)_(b3), and X₄ may be N; or

T₁ may be N, T₂ may be C, X₂ may be C-(L₂)_(a2)-(R₂)_(b2), X₃ may be N, and X₄ may be N,

iii) in the Formula 1C,

X₁ may be O, S, or N-[(L₁)_(a1)-(R₁)_(b1)], T₃ and T₄ may be C, X₄ may be N, and X₅ may be C-(L₅)_(a5)-(R₅)_(c5), or

iv) in Formula 1D,

T₁ may be N, T₂ may be C, T₃ and T₄ may be C, X₄ may be N or C-(L₄)_(a4)-(R₄)_(b4).

X₂₁ in Formulae 2A and 2B may be selected from O, S, Se, C(R₂₃)(R₂₄), Si(R₂₃)(R₂₄), and N-[(L₂₁)_(a21)-(R₂₁)_(b21)].

In various embodiments, X₂₁ in Formulae 2A and 2B may be N[(L₂₁)_(a21)-(R₂₁)_(b21)].

In various embodiments, X₂₁ in Formulae 2A and 2B may be O, S, Se, C(R₂₃)(R₂₄), or Si(R₂₃)(R₂₄), and

at least one selected from rings A₂₁, A₂₂, and A₂₃ in Formula 2A and at least one selected from rings A₂₁ and A₂₃ in Formula 2B may each independently be selected from groups represented by Formulae 2-1 to 2-3, 2-10 to 2-27, and 2-33 to 2-36, and X₂₂ or X₂₃ in Formulae 2-1 to 2-3, 2-10 to 2-27, and 2-33 to 2-36 may be N-[(L₂₂)_(a22)-(R₂₂)_(b22)].

In various embodiments, X₂₁ in Formulae 2A and 2B may be O, S, Se, C(R₂₃)(R₂₄), or Si(R₂₃)(R₂₄), and

at least one selected from rings A₂₁, A₂₂, and A₂₃ in Formula 2A and at least one selected from rings A₂₁ and A₂₃ in Formula 2B may be selected from groups represented by Formulae 2-101 to 2-103, 2-147 to 2-211, 2-214 to 2-219, and 2-226 to 2-229, and X₂₂ or X₂₃ in Formulae 2-101 to 2-103, 2-147 to 2-21 1, 2-214 to 2-219, and 2-226 to 2-229 may be N-[(L₂₂)_(a22)-(R₂₂)_(b22)], but embodiments are not limited thereto.

In Formulae 2A and 2B, X₂₁ may be O, S, Se, C(R₂₃)(R₂₄), Si(R₂₃)(R₂₄), or N-[(L₂₁)_(a21)-(R₂₁)_(b21)], and X₂₂ and X₂₃ may each independently be O, S, Se, C(R₂₅)(R₂₆), Si(R₂₅)(R₂₆), or N-[(L₂₂)_(a22)-(R₂₂)_(b22)]. Descriptions of L₂₁, L₂₂, a21, a22, R₂₁ to R₂₆, b21, and b22 are the same as described below.

L₁ to L₅, L₁₁, L₁₂, L₂₁, and L₂₂ in Formulae 1A to 1D, 2A, and 2B may each independently be selected from a substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀ arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group.

For example, in Formulae 1A to 1D, 2A, and 2B,

L₁ to L₅, L₁₁, L₁₂, L₂₁, and L₂₂ may each independently be selected from the group consisting of:

a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, a heptalenylene group, an indacenylene group, an acenaphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a spiro-benzofluorene-fluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a naphthacenylene group, a picenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a rubicenylene group, a coronenylene group, an ovalenylene group, a pyrrolylene group, a thiophenylene group, a furanylene group, a silolylene group, an imidazolylene group, a pyrazolylene group, a thiazolylene group, an isothiazolylene group, an oxazolylene group, an isoxazolylene group, a pyridinylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, an indolylene group, an isoindolylene group, an indazolylene group, a purinylene group, a quinolinylene group, an isoquinolinylene group, a benzoquinolinylene group, a phthalazinylene group, a naphthyridinylene group, a quinoxalinylene group, a quinazolinylene group, a cinnolinylene group, a phenanthridinylene group, an acridinylene group, a phenanthrolinylene group, a phenazinylene group, a benzimidazolylene group, a benzofuranylene group, a benzothiophenylene group, a benzosilolylene group, an isobenzothiazolylene group, a benzoxazolylene group, an isobenzoxazolylene group, a triazolylene group, a tetrazolylene group, an oxadiazolylene group, a triazinylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a dibenzosilolylene group, a carbazolylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a thiadiazolylene group, an imidazopyridinylene group, an imidazopyrimidinylene group, an oxazolopyridinylene group, a thiazolopyridinylene group, a benzonaphthyridinylene group, an azafluorenylene group, an azaspiro-bifluorenylene group, an azacarbazolylene group, an azadibenzofuranylene group, an azadibenzothiophenylene group, and an azadibenzosilolylene group; and

a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, a heptalenylene group, an indacenylene group, an acenaphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a spiro-benzofluorene-fluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a naphthacenylene group, a picenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a rubicenylene group, a coronenylene group, an ovalenylene group, a pyrrolylene group, a thiophenylene group, a furanylene group, a silolylene group, an imidazolylene group, a pyrazolylene group, a thiazolylene group, an isothiazolylene group, an oxazolylene group, an isoxazolylene group, a pyridinylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, an indolylene group, an isoindolylene group, an indazolylene group, a purinylene group, a quinolinylene group, an isoquinolinylene group, a benzoquinolinylene group, a phthalazinylene group, a naphthyridinylene group, a quinoxalinylene group, a quinazolinylene group, a cinnolinylene group, a phenanthridinylene group, an acridinylene group, a phenanthrolinylene group, a phenazinylene group, a benzimidazolylene group, a benzofuranylene group, a benzothiophenylene group, a benzosilolylene group, an isobenzothiazolylene group, a benzoxazolylene group, an isobenzoxazolylene group, a triazolylene group, a tetrazolylene group, an oxadiazolylene group, a triazinylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a dibenzosilolylene group, a carbazolylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a thiadiazolylene group, an imidazopyridinylene group, an imidazopyrimidinylene group, an oxazolopyridinylene group, a thiazolopyridinylene group, a benzonaphthyridinylene group, an azafluorenylene group, an azaspiro-bifluorenylene group, an azacarbazolylene group, an azadibenzofuranylene group, an azadibenzothiophenylene group, and an azadibenzosilolylene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, a terphenyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ may each independently be selected from the group consisting of:

a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, and a quinazolinyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, and a quinazolinyl group, each substituted with at least one selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, and a phenyl group,

but embodiments are not limited thereto.

In various embodiments,

L₁ to L₅, L₁₁, L₁₂, L₂₁, and L₂₂ in Formulae 1A to 1D, 2A, and 2B may each independently be selected from groups represented by Formulae 3-1 to 3-101:

wherein, in Formulae 3-1 to 3-101,

Y₁ may be O, S, C(Z₃)(Z₄), N(Z₅), or Si(Z₆)(Z₇),

Z₁ to Z₇ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, a benzonaphthyridinyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, an azadibenzosilolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

Z₃ and Z₄ may be optionally connected to each other to form a saturated or unsaturated ring,

descriptions of Q₃₁ to Q₃₃ are the same as described herein,

d2 may be an integer selected from 0 to 2,

d3 may be an integer selected from 0 to 3,

d4 may be an integer selected from 0 to 4,

d5 may be an integer selected from 0 to 5,

d6 may be an integer selected from 0 to 6,

d8 may be an integer selected from 0 to 8, and

* and *′ each independently indicate a binding site to a neighboring atom.

a1 in Formulae 1A to 1D, 2A, and 2B indicates the number of L₁(s) and may be an integer selected from 0 to 5. When a1 is zero, *-(L₁)_(a1)-*′ may be a single bond, and when a1 is two or more, two or more L₁(s) may be identical to or different from each other. Descriptions of a2 to a5, a11, a12, a21, and a22 may each independently be understood by referring to the description presented in connection with a1 and the corresponding structures of Formulae 1A to 1D, 2A, and 2B.

For example, a1 to a5, a11, a12, a21, and a22 may each independently be 0, 1, 2, or 3.

R₁ to R₅, R₁₁, R₁₂, R₂₁ to R₂₄, R₂₇, and R₂₈ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂), wherein Q₁ to Q₃ are defined below.

For example, R₁ to R₅, R₁₁, and R₁₂ may each independently be selected from the group consisting of:

hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, and a hydrazono group;

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a spiro-benzofluorene-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an oxazolopyridinyl group, a thiazolopyridinyl group, a benzonaphthyridinyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, an azadibenzosilolyl group, a benzofuranopyrimidinyl group, a benzothiopheno pyrimidyl group, a pyrimidinoquinoxalinyl group, and an azaindenopyridinyl group; and

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a spiro-benzofluorene-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an oxazolopyridinyl group, a thiazolopyridinyl group, a benzonaphthyridinyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, an azadibenzosilolyl group, a benzofuranopyrimidinyl group, a benzothiophenopyrimidyl group, a pyrimidinoquinoxalinyl group, and an azaindenopyridinyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, a terphenyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₁ to Q₃ and Q₃₁ to Q₃₃ may each independently be selected from the group consisting of:

a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, and a quinazolinyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, and a quinazolinyl group, each substituted with at least one selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, and a phenyl group.

Descriptions of Q₁ to Q₃ and Q₃₁ to Q₃₃ may be the same as described herein.

In various embodiments,

R₂₁ to R₂₄, R₂₇, and R₂₈ may each independently be selected from the group consisting of:

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a spiro-benzofluorene-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an oxazolopyridinyl group, a thiazolopyridinyl group, a benzonaphthyridinyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, and an azadibenzosilolyl group; and

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a spiro-benzofluorene-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an oxazolopyridinyl group, a thiazolopyridinyl group, a benzonaphthyridinyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, and an azadibenzosilolyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, a terphenyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and

R₂₂ may be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, —Si(Q₁)(Q₂)(Q₃), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂),

wherein descriptions of Q₁ to Q₃ and Q₃₁ to Q₃₃ are the same as described herein.

In various embodiments,

R₂₁, R₂₃, R₂₄, R₂₇, and R₂₈ in Formulae 2A and 2B may each independently be selected from groups represented by Formulae 5-1 to 5-49 and 6-1 to 6-124, and

R₁ to R₅, R₁₁, R₁₂, and R₂₂ in Formulae 1A to 1D, 2A, and 2B may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a group represented by any of Formulae 5-1 to 5-49 and 6-1 to 6-124, —Si(Q₁)(Q₂)(Q₃), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂), but embodiments are not limited thereto:

wherein, in Formulae 5-1 to 5-49 and 6-1 to 6-128,

Y₃₁ and Y₃₂ may each independently be O, S, C(Z₃₃)(Z₃₄), N(Z₃₅), or Si(Z₃₆)(Z₃₇), Y₄₁ may be N or C(Z₄₁), Y₄₂ may be N or C(Z₄₂), Y₄₃ may be N or C(Z₄₃), Y₄₄ may be N or C(Z₄₄), Y₅₁ may be N or C(Z₅₁), Y₅₂ may be N or C(Z₅₂), Y₅₃ may be N or C(Z₅₃), Y₅₄ may be N or C(Z₅₄), at least one selected from Y₄₁ to Y₄₃ and Y₅₁ to Y₅₄ in Formulae 6-118 to 6-121 may be N, and Y₄₁ to Y₄₄ and Y₅₁ to Y₅₄ in Formula 6-122 may be N,

Z₃₁ to Z₃₈, Z₄₁ to Z₄₄, and Z₅₁ to Z₅₄ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, a benzonaphthyridinyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, an azadibenzosilolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), and —P(═O)(Q₃₁)(Q₃₂),

wherein descriptions of Q₃₁ to Q₃₃ are the same as described herein, and descriptions of Q₁ to Q₃ are the same as the description provided above in connection with Q₃₁,

e2 may be an integer selected from 0 to 2,

e3 may be an integer selected from 0 to 3,

e4 may be an integer selected from 0 to 4,

e5 may be an integer selected from 0 to 5,

e6 may be an integer selected from 0 to 6,

e7 may be an integer selected from 0 to 7,

e9 may be an integer selected from 0 to 9, and

* indicates a binding site to a neighboring atom.

In various embodiments,

R₂₁, R₂₃, R₂₄, R₂₇, and R₂₈ in Formulae 2A and 2B may each independently be selected from groups represented by Formulae 9-1 to 9-100 and 10-1 to 10-121,

R₁ to R₅, R₁₁, R₁₂, and R₂₂ in Formulae 1A to 1D, 2A, and 2B may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a group represented by any of Formulae 9-1 to 9-100 and 10-1 to 10-121, —Si(Q₁)(Q₂)(Q₃), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂), but embodiments are not limited thereto:

wherein, in Formulae 9-1 to 9-100 and 10-1 to 10-121, Ph may refer to a phenyl group, “D” may refer to deuterium, and * indicates a binding site to a neighboring atom.

R₄ and R₅ in Formulae 1A to 1D may be optionally connected to each other to form a saturated or unsaturated ring.

b1 in Formulae 1A to 1D indicates the number of R₁(s), wherein when b1 is two or more, two or more R₁(s) may be identical to or different from each other. Descriptions of b2 to b5, b11, and b12 may each independently be understood by referring to the description presented in connection with b1 and the corresponding structures of Formulae 1A to 1D.

b1 to b5, b11, and b12 in Formulae 1A to 1D may each independently be an integer selected from 0 to 4. For example, b1 to b5, b11, and b12 may each independently be 0 or 1, but are not limited thereto.

b21 in Formulae 2A and 2B indicates the number of R₂₁(s), wherein when b21 is two or more, two or more R₂₁(s) may be identical to or different from each other. Description of b22 may be understood by referring to the description presented in connection with b21 and the corresponding structures of Formulae 2A and 2B.

b21 and b22 in Formulae 2A and 2B may each independently be an integer selected from 0 to 4. For example, b21 and b22 may each independently be 1 or 2, but are not limited thereto.

In various embodiments, the first compound may be represented by one selected from Formulae 1A(1) to 1A(11), 1B(1), 1B(2), 1C(1) to 1C(4), 1D(1), and 1D(2):

wherein descriptions of ring A₁, ring A₂, L₁ to L₅, a1 to a5, R₁ to R₅, and b1 to b5 in Formulae 1A(1) to 1A(11), 1B(1), 1B(2), 1C(1) to 1C(4), 1D(1), and 1D(2) are the same as described herein.

In various embodiments, the first compound may be one selected from Compounds 1-1 to 1-284:

In various embodiments, the second compound may be selected from Compounds 2-1a to 2-172a and 2-1 to 2-262, but is not limited thereto:

Any combinations of ring A₁, ring A₂, L₁ to L₅, L₁₁, L₁₂, a1 to a5, a11, a12, R₁ to R₅, R₁₁, R₁₂, b1 to b5, b11, and b12 in Formulae 1A to 1D may be embodied within the scope described herein.

Any combinations of ring A₂₁, ring A₂₂, ring A₂₃, X₂₁, and T₁₁ to T₁₄ may be embodied within the scope described herein.

Any combinations of *-[(L₂₂)_(a22)-(R₂₂)_(b22)], C(R₂₃)(R₂₄), Si(R₂₃)(R₂₄), and N-[(L₂₁)_(a21)-(R₂₁)_(b21)] may be embodied within the scope of descriptions of L₂₁, L₂₂, a21, a22, R₂₁ to R₂₄, b21, and b22 provided herein.

In various embodiments, the hole transport region may include an emission auxiliary layer, the emission auxiliary layer may directly contact the emission layer, and the second compound may be included in the emission auxiliary layer.

In various embodiments, the electron transport region may include a buffer layer, the buffer layer may directly contact the emission layer, and the second compound may be included in the buffer layer, but embodiments are not limited thereto.

When both the hole transport region and the electron transport region in the organic light-emitting device include the second compound described above, the second compound included in the hole transport region and the second compound included in the electron transport region may be identical to or different from each other.

The electron transport region may include an electron transport layer, and the first compound may be included in the electron transport layer.

In various embodiments, the electron transport region may include a buffer layer and an electron transport layer (between the buffer layer and the second electrode), the second compound may be included in the buffer layer, and the first compound may be included in the electron transport layer.

[Description of FIG. 1 ]

FIG. 1 is a schematic view of an organic light-emitting device 10 according to an embodiment. The organic light-emitting device 10 may include a first electrode 110, an organic layer 150, and a second electrode 190.

Hereinafter, the structure of the organic light-emitting device 10 according to an embodiment and a method of manufacturing the organic light-emitting device 10 will be described in connection with FIG. 1 .

[First Electrode 110]

In FIG. 1 , a substrate may be additionally disposed (e.g., positioned) under the first electrode 110 or above the second electrode 190. The substrate may be a glass substrate or a plastic substrate, each having excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and/or water-resistance.

The first electrode 110 may be formed by depositing or sputtering a material for forming the first electrode 110 on the substrate. When the first electrode 110 is an anode, the material for forming the first electrode may be selected from materials with a high work function to facilitate hole injection.

The first electrode 110 may be a reflective electrode, a semi-transmissive electrode, or a transmissive electrode. When the first electrode 110 is a transmissive electrode, a material for forming the first electrode may be selected from indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO₂), zinc oxide (ZnO), and combinations thereof, but is not limited thereto. In various embodiments, when the first electrode 110 is a semi-transmissive electrode or a reflective electrode, a material for forming the first electrode may be selected from magnesium(Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), and combinations thereof, but is not limited thereto.

The first electrode 110 may have a single-layered structure, or a multi-layered structure including two or more layers. For example, the first electrode 110 may have a three-layered structure of ITO/Ag/ITO, but the structure of the first electrode 110 is not limited thereto.

[Organic Layer 150]

The organic layer 150 may be disposed on the first electrode 110. The organic layer 150 may include an emission layer.

The organic layer 150 may include a hole transport region between the first electrode 110 and the emission layer, and an electron transport region between the emission layer and the second electrode 190.

[Hole Transport Region in Organic Layer 150]

The hole transport region may have i) a single-layered structure including a single layer including a single material, ii) a single-layered structure including a single layer including a plurality of different materials, or iii) a multi-layered structure having a plurality of layers including a plurality of different materials.

The hole transport region may include at least one layer selected from a hole injection layer, a hole transport layer, an emission auxiliary layer, and an electron blocking layer.

For example, the hole transport region may have a single-layered structure including a single layer including a plurality of different materials, or a multi-layered structure having a structure of hole injection layer/hole transport layer, hole injection layer/hole transport layer/emission auxiliary layer, hole injection layer/emission auxiliary layer, hole transport layer/emission auxiliary layer, or hole injection layer/hole transport layer/electron blocking layer, wherein for each structure, constituting layers are sequentially stacked from the first electrode 110 in this stated order, but the structure of the hole transport region is not limited thereto.

The hole transport region may include the second compound as described above.

In various embodiments, the hole transport region may include an emission auxiliary layer. The emission auxiliary layer may directly contact the emission layer.

In various embodiments, the hole transport region may include a hole injection layer and a hole transport layer, which are stacked in this stated order on the first electrode 110; a hole injection layer and an emission auxiliary layer, which are stacked in this stated order on the first electrode 110; or a hole injection layer, a hole transport layer, and an emission auxiliary layer, which are stacked in this stated order on the first electrode 110, but the structure of the hole transport region is not limited thereto.

When the hole transport region includes an emission auxiliary layer, the emission auxiliary layer may further include the second compound.

The hole transport region may include at least one selected from m-MTDATA, TDATA, 2-TNATA, NPB(NPD), β-NPB, TPD, spiro-TPD, spiro-NPB, methylated NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA), polyaniline/dodecylbenzenesulfonic acid (Pani/DBSA), poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS), polyaniline/camphor sulfonic acid (Pani/CSA), polyaniline/poly(4-styrenesulfonate) (Pani/PSS), a compound represented by Formula 201, and a compound represented by Formula 202:

wherein, in Formulae 201 and 202,

L₂₀₁ to L₂₀₄ may each independently be selected from a substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀ arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

L₂₀₅ may be selected from *—O—*′, *—S—*′, *—N(Q₂₀₁)-*′, a substituted or unsubstituted C₁-C₂₀ alkylene group, a substituted or unsubstituted C₂-C₂₀ alkenylene group, a substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀ arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

xa1 to xa4 may each independently be an integer selected from 0 to 3,

xa5 may be an integer selected from 1 to 10, and

R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independently be selected from a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group.

For example, in Formula 202, R₂₀₁ and R₂₀₂ may be optionally connected to each other via a single bond, a dimethyl-methylene group, or a diphenyl-methylene group; and R₂₀₃ and R₂₀₄ may be optionally connected to each other via a single bond, a dimethyl-methylene group, or a diphenyl-methylene group.

In various embodiments, in Formulae 201 and 202,

L₂₀₁ to L₂₀₅ may each independently be selected from the group consisting of:

a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, a heptalenylene group, an indacenylene group, an acenaphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a naphthacenylene group, a picenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a rubicenylene group, a coronenylene group, an ovalenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, and a pyridinylene group; and

a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, a heptalenylene group, an indacenylene group, an acenaphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a naphthacenylene group, a picenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a rubicenylene group, a coronenylene group, an ovalenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, and a pyridinylene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with —F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), and —N(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and a naphthyl group.

In various embodiments, xa1 to xa4 may each independently be 0, 1, or 2.

In various embodiments, xa5 may be 1, 2, 3, or 4.

In various embodiments, R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independently be selected from the group consisting of:

a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with —F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), and —N(Q₃₁)(Q₃₂),

wherein descriptions of Q₃₁ to Q₃₃ are the same as described herein.

In various embodiments, at least one selected from R₂₀₁ to R₂₀₃ in Formula 201 may each independently be selected from the group consisting of:

a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group; and

a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with —F, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group,

but embodiments of the present disclosure are not limited thereto.

In various embodiments, in Formula 202, i) R₂₀₁ and R₂₀₂ may be connected to each other via a single bond, and/or ii) R₂₀₃ and R₂₀₄ may be connected to each other via a single bond.

In various embodiments, at least one selected from R₂₀₁ to R₂₀₄ in Formula 202 may be selected from the group consisting of:

a carbazolyl group; and

a carbazolyl group substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with —F, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group,

but is not limited thereto.

The compound represented by Formula 201 may be represented by Formula 201A:

For example, the compound represented by Formula 201 may be represented by Formula 201A(1), but is not limited thereto:

In various embodiments, the compound represented by Formula 201 may be represented by Formula 201A-1, but is not limited thereto:

The compound represented by Formula 202 may be represented by Formula 202A:

In various embodiments, the compound represented by Formula 202 may be represented by Formula 202A-1:

In Formulae 201A, 201A(1), 201A-1, 202A, and 202A-1,

descriptions of L₂₀₁ to L₂₀₃, xa1 to xa3, xa5, and R₂₀₂ to R₂₀₄ are the same as described herein,

descriptions of R₂₁₁ and R₂₁₂ may each independently be the same as the description provided in connection with R₂₀₃, and

R₂₁₃ to R₂₁₇ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with —F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group.

The hole transport region may include at least one compound selected from Compounds HT1 to HT39, but is not limited thereto:

A thickness of the hole transport region may be in a range of about 100 Å to about 10,000 Å, for example, about 100 Å to about 1,000 Å. When the hole transport region includes at least one selected from a hole injection layer and a hole transport layer, a thickness of the hole injection layer may be in a range of about 100 Å to about 9,000 Å, for example, about 100 Å to about 1,000 Å, and a thickness of the hole transport layer may be in a range of about 50 Å to about 2,000 Å, for example, about 100 Å to about 1,500 Å. When the thicknesses of the hole transport region, the hole injection layer, and the hole transport layer are within these any of these ranges, satisfactory (or suitable) hole transporting characteristics may be obtained without a substantial increase in driving voltage.

The emission auxiliary layer may increase light-emission efficiency by compensating for an optical resonance distance according to the wavelength of light emitted by an emission layer, and the electron blocking layer may block or reduce the flow of electrons from an electron transport region. The emission auxiliary layer and the electron blocking layer may each independently include any of the materials as described above.

[p-dopant]

The hole transport region may further include, in addition to the materials described above, a charge-generation material for the improvement of conductive properties. The charge-generation material may be homogeneously or non-homogeneously dispersed in the hole transport region.

The charge-generation material may be, for example, a p-dopant.

In various embodiments, a lowest unoccupied molecular orbital (LUMO) of the p-dopant may be −3.5 eV or less.

The p-dopant may include at least one selected from a quinone derivative, a metal oxide, and a cyano group-containing compound, but embodiments are not limited thereto.

For example, the p-dopant may include at least one selected from the group consisting of:

a quinone derivative, such as tetracyanoquinodimethane (TCNQ) and/or 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ);

a metal oxide, such as tungsten oxide and/or molybdenum oxide;

1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile (HAT-CN); and

a compound represented by Formula 221 below,

but is not limited thereto:

In Formula 221,

R₂₂₁ to R₂₂₃ may each independently be selected from a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, wherein at least one selected from R₂₂₁ to R₂₂₃ has at least one substituent selected from a cyano group, —F, —Cl, —Br, —I, a C₁-C₂₀ alkyl group substituted with —F, a C₁-C₂₀ alkyl group substituted with —Cl, a C₁-C₂₀ alkyl group substituted with —Br, and a C₁-C₂₀ alkyl group substituted with —I.

[Emission Layer in Organic Layer 150]

When the organic light-emitting device 10 is a full color organic light-emitting device, the emission layer may be patterned into a red emission layer, a green emission layer, and/or a blue emission layer, according to a sub-pixel. In various embodiments, the emission layer may have a stacked structure of two or more layers selected from a red emission layer, a green emission layer, and a blue emission layer, in which the two or more layers contact each other or are separated from each other. In various embodiments, the emission layer may include two or more materials selected from a red-light emission material, a green-light emission material, and a blue-light emission material, in which the two or more materials are mixed with each other in a single layer to emit white light.

In various embodiments, the emission layer of the organic light-emitting device 10 may be a first-color-light emission layer,

the organic light-emitting device 10 may further include i) at least one second-color-light emission layer or ii) at least one second-color-light emission layer and at least one third-color-light emission layer, between the first electrode 110 and the second electrode 190,

a maximum emission wavelength of the first-color-light emission layer, a maximum emission wavelength of the second-color-light emission layer, and a maximum emission wavelength of the third-color-light emission layer may be identical to or different from each other, and

the organic light-emitting device 10 may emit mixed light including first-color-light and second-color-light, or mixed light including first-color-light, second-color-light, and third-color-light, but embodiments of the present disclosure are not limited thereto.

For example, the maximum emission wavelength of the first-color-light emission layer may be different from a maximum emission wavelength of the second-color-light emission layer, and the mixed light including first-color-light and second-color-light may be white light, but embodiments are not limited thereto.

In various embodiments, the maximum emission wavelength of the first-color-light emission layer, the maximum emission wavelength of the second-color-light emission layer, and the maximum emission wavelength of the third-color-light emission layer may be different from one another, and the mixed light including first-color-light, second-color-light, and third-color-light may be white light. However, embodiments are not limited thereto.

The emission layer may include a host and a dopant. The dopant may include at least one selected from a phosphorescent dopant and a fluorescent dopant.

An amount of the dopant in the emission layer may be, for example, in a range of about 0.01 to about 15 parts by weight based on 100 parts by weight of the host, but is not limited thereto.

A thickness of the emission layer may be in a range of about 100 Å to about 1,000 Å, for example, about 200 Å to about 600 Å. When the thickness of the emission layer is within any of these ranges, excellent (or suitable) light-emission characteristics may be obtained without a substantial increase in driving voltage.

[Host in Emission Layer]

In various embodiments, the host may include a compound represented by Formula 301 below. [Ar₃₀₁]_(xb11)-[(L₃₀₁)_(xb1)-R₃₀₁]_(xb21)  Formula 301

In Formula 301,

Ar₃₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclic group,

xb11 may be 1, 2, or 3,

L₃₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀ arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

xb1 may be an integer selected from 0 to 5,

R₃₀₁ may be selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₃₀₁)(Q₃₀₂)(Q₃₀₃), —N(Q₃₀₁)(Q₃₀₂), —B(Q₃₀₁)(Q₃₀₂), —C(═O)(Q₃₀₁), —S(═O)₂(Q₃₀₁), and —P(═O)(Q₃₀₁)(Q₃₀₂), and

xb21 may be an integer selected from 1 to 5,

wherein Q₃₀₁ to Q₃₀₃ may each independently be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and a naphthyl group, but embodiments are not limited thereto.

In various embodiments, Ar₃₀₁ in Formula 301 may be selected from the group consisting of:

a naphthalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, an indenoanthracene group, a dibenzofuran group, and a dibenzothiophene group; and

a naphthalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, an indenoanthracene group, a dibenzofuran group, and a dibenzothiophene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and a naphthyl group, but embodiments are not limited thereto.

When xb11 in Formula 301 is two or more, adjacent Ar₃₀₁(s) may be connected to each other via a single bond.

In various embodiments, the compound represented by Formula 301 may be represented by Formula 301-1 or 301-2:

wherein, in Formulae 301-1 to 301-2,

A₃₀₁ to A₃₀₄ may each independently be selected from a benzene group, a naphthalene group, a phenanthrene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a pyridine group, a pyrimidine group, an indene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, an indole group, a carbazole group, a benzocarbazole group, a dibenzocarbazole group, a furan group, a benzofuran group, a dibenzofuran group, a naphthofuran group, a benzonaphthofuran group, a dinaphthofuran group, a thiophene group, a benzothiophene group, a dibenzothiophene group, a naphthothiophene group, a benzonaphthothiophene group, and a dinaphthothiophene group,

X₃₀₁ may be O, S, or N-[(L₃₀₄)_(xb4)-R₃₀₄],

R₃₁₁ to R₃₁₄ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

xb22 and xb23 may each independently be 0, 1, or 2,

descriptions of L₃₀₁, xb1, R₃₀₁, and Q₃₁ to Q₃₃ are the same as described herein,

descriptions of L₃₀₂ to L₃₀₄ may each independently be the same as the description provided in connection with L₃₀₁,

descriptions of xb2 to xb4 may each independently be the same as the description provided in connection with xb1, and

descriptions of R₃₀₂ to R₃₀₄ may each independently be the same as the description provided in connection with R₃₀₁.

For example, L₃₀₁ to L₃₀₄ in Formulae 301, 301-1, and 301-2 may each independently be selected from the group consisting of:

a phenylene group, a naphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, a pyridinylene group, an imidazolylene group, a pyrazolylene group, a thiazolylene group, an isothiazolylene group, an oxazolylene group, an isoxazolylene group, a thiadiazolylene group, an oxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, a triazinylene group, a quinolinylene group, an isoquinolinylene group, a benzoquinolinylene group, a phthalazinylene group, a naphthyridinylene group, a quinoxalinylene group, a quinazolinylene group, a cinnolinylene group, a phenanthridinylene group, an acridinylene group, a phenanthrolinylene group, a phenazinylene group, a benzimidazolylene group, an isobenzothiazolylene group, a benzoxazolylene group, an isobenzoxazolylene group, a triazolylene group, a tetrazolylene group, an imidazopyridinylene group, an imidazopyrimidinylene group, and an azacarbazolylene group; and

a phenylene group, a naphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, a pyridinylene group, an imidazolylene group, a pyrazolylene group, a thiazolylene group, an isothiazolylene group, an oxazolylene group, an isoxazolylene group, a thiadiazolylene group, an oxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, a triazinylene group, a quinolinylene group, an isoquinolinylene group, a benzoquinolinylene group, a phthalazinylene group, a naphthyridinylene group, a quinoxalinylene group, a quinazolinylene group, a cinnolinylene group, a phenanthridinylene group, an acridinylene group, a phenanthrolinylene group, a phenazinylene group, a benzimidazolylene group, an isobenzothiazolylene group, a benzoxazolylene group, an isobenzoxazolylene group, a triazolylene group, a tetrazolylene group, an imidazopyridinylene group, an imidazopyrimidinylene group, and an azacarbazolylene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ are the same as described herein.

In various embodiments, R₃₀₁ to R₃₀₄ in Formulae 301, 301-1, and 301-2 may each independently be selected from the group consisting of:

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, and an azacarbazolyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, and an azacarbazolyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ are the same as described herein.

In various embodiments, the host may include an alkaline earth-metal complex. For example, the host may be selected from a Be complex (e.g., Compound H55), a Mg complex, and a Zn complex.

The host may include at least one selected from 9,10-di(2-naphthyl)anthracene (herein referred to as AND or ADN), 2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN), 9,10-di-(2-naphthyl)-2-t-butyl-anthracene (TBADN), 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP), 1,3-di-9-carbazolylbenzene (mCP), TCP (1,3,5-tri(carbazol-9-yl)benzene), and Compounds H1 to H55, but is not limited thereto:

[Phosphorescent Dopant Included in Emission Layer in Organic Layer 150]

The phosphorescent dopant may include an organometallic complex represented by Formula 401 below:

wherein, in Formulae 401 and 402,

M may be selected from iridium (Ir), platinum (Pt), palladium (Pd), osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), rhodium (Rh), and thulium (Tm),

L₄₀₁ may be selected from ligands represented by Formula 402, and xc1 may be 1, 2, or 3, wherein when xc1 is two or more, two or more L₄₀₁(s) may be identical to or different from each other,

L₄₀₂ may be an organic ligand, and xc2 may be an integer selected from 0 to 4, wherein xc2 is two or more, two or more L₄₀₂(s) may be identical to or different from each other,

X₄₀₁ to X₄₀₄ may each independently be nitrogen or carbon,

X₄₀₁ and X₄₀₃ may be connected to each other via a single bond or a double bond, and X₄₀₂ and X₄₀₄ may be connected to each other via a single bond or a double bond,

A₄₀₁ and A₄₀₂ may each independently be a C₅-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group,

X₄₀₅ may be a single bond, *—O—*′, *—C(═O)—*′, *—N(Q₄₁₁)-*′, *—C(Q₄₁₁)(Q₄₁₂)-*′, *—C(Q₄₁₁)=C(Q₄₁₂)-*′, *—C(Q₄₁₁)=*′, or *═C(Q₄₁₁)=*′, wherein Q₄₁₁ and Q₄₁₂ may each independently be hydrogen, deuterium, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group,

X₄₀₆ may be a single bond, O, or S,

R₄₀₁ and R₄₀₂ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a substituted or unsubstituted C₁-C₂₀ alkyl group, a substituted or unsubstituted C₁-C₂₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), —N(Q₄₀₁)(Q₄₀₂), —B(Q₄₀₁)(Q₄₀₂), —C(═O)(Q₄₀₁), —S(═O)₂(Q₄₀₁), and —P(═O)(Q₄₀₁)(Q₄₀₂), wherein Q₄₀₁ to Q₄₀₃ may each independently be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a C₆-C₂₀ aryl group, and a C₁-C₂₀ heteroaryl group,

xc11 and xc12 may each independently be an integer selected from 0 to 10, and

* and *′ in Formula 402 may each independently indicate a binding site to M in Formula 401.

In various embodiments, A₄₀₁ and A₄₀₂ in Formula 402 may each independently be selected from a benzene group, a naphthalene group, a fluorene group, a spiro-bifluorene group, an indene group, a pyrrole group, a thiophene group, a furan group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a quinoxaline group, a quinazoline group, a carbazole group, a benzimidazole group, a benzofuran group, a benzothiophene group, an isobenzothiophene group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a dibenzofuran group, and a dibenzothiophene group.

In various embodiments, in Formula 402, i) X₄₀₁ may be nitrogen and X₄₀₂ may be carbon, or ii) both X₄₀₁ and X₄₀₂ may be nitrogen.

In various embodiments, R₄₀₁ and R₄₀₂ in Formula 402 may each independently be selected from the group consisting of:

hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a phenyl group, a naphthyl group, a cyclopentyl group, a cyclohexyl group, an adamantanyl group, a norbornanyl group, and a norbornenyl group;

a cyclopentyl group, a cyclohexyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group;

a cyclopentyl group, a cyclohexyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group; and

—Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), —N(Q₄₀₁)(Q₄₀₂), —B(Q₄₀₁)(Q₄₀₂), —C(═O)(Q₄₀₁), —S(═O)₂(Q₄₀₁), and —P(═O)(Q₄₀₁)(Q₄₀₂),

wherein Q₄₀₁ to Q₄₀₃ may each independently be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, and a naphthyl group, but embodiments are not limited thereto.

In various embodiments, when xc1 in Formula 401 is two or more, two A₄₀₁(s) selected from two or more L₄₀₁(s) may be optionally connected to each other via a linking group X₄₀₇, and/or two A₄₀₂(s) may be optionally connected to each other via a linking group X₄₀₈ (see Compounds PD1 to PD4 and PD7). X₄₀₇ and X₄₀₈ may each independently be a single bond, *—O—*′, *—S—*′, *—C(═O)—*′, *—N(Q₄₁₃)-*′, *—C(Q₄₁₃)(Q₄₁₄)-*′, or *—C(Q₄₁₃)=C(Q₄₁₄)-*′ (wherein Q₄₁₃ and Q₄₁₄ may each independently be hydrogen, deuterium, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group), but are not limited thereto.

L₄₀₂ in Formula 401 may be any monovalent, divalent, or trivalent organic ligand. For example, L₄₀₂ may be selected from a halogen ligand, a diketone ligand (e.g., an acetylacetonate), a carboxylic acid ligand (e.g., a picolinate), —C(═O), an isonitrile, —CN, and phosphorus ligand (e.g., a phosphine and/or a phosphite), but is not limited thereto.

In various embodiments, the phosphorescent dopant may be selected from, for example, Compounds PD1 to PD25, but is not limited thereto:

[Fluorescent Dopant in Emission Layer]

The fluorescent dopant may include an arylamine compound or a styrylamine compound.

In various embodiments, the fluorescent dopant may include a compound represented by Formula 501:

In Formula 501,

Ar₅₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclic group,

L₅₀₁ to L₅₀₃ may each independently be selected from a substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀ arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

xd1 to xd3 may each independently be an integer selected from 0 to 3,

R₅₀₁ and R₅₀₂ may each independently be selected from a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, and

xd4 may be an integer selected from 1 to 6.

In various embodiments, Ar₅₀₁ in Formula 501 may be selected from the group consisting of:

a naphthalene group, a heptalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, an indenoanthracene group, and an indenophenanthrene group; and

a naphthalene group, a heptalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, an indenoanthracene group, and an indenophenanthrene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and a naphthyl group.

In various embodiments, L₅₀₁ to L₅₀₃ in Formula 501 may each independently be selected from the group consisting of:

a phenylene group, a naphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, and a pyridinylene group; and

a phenylene group, a naphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, and a pyridinylene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group.

In various embodiments, R₅₀₁ and R₅₀₂ in Formula 501 may each independently be selected from the group consisting of:

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, and —Si(Q₃₁)(Q₃₂)(Q₃₃),

wherein Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and a naphthyl group.

In various embodiments, xd4 in Formula 501 may be 2, but is not limited thereto.

For example, the fluorescent dopant may be selected from Compounds FD1 to FD22:

In various embodiments, the fluorescent dopant may be selected from compounds illustrated below, but is not limited thereto:

[Electron Transport Region in Organic Layer 150]

The electron transport region may have i) a single-layered structure having (e.g., consisting of) a single layer including a single material, ii) a single-layered structure having (e.g., consisting of) a single layer including a plurality of different materials, or iii) a multi-layered structure having a plurality of layers including a plurality of different materials.

The electron transport region may include a buffer layer, a hole blocking layer, an electron control layer, an electron transport layer, an electron injection layer, or any combination thereof, but is not limited thereto.

In various embodiments, the electron transport region may include the first compound and the second compound. The first compound and the second compound are the same as described herein.

In various embodiments, the electron transport region may include an electron transport layer and a buffer layer (between the emission layer and the electron transport layer), wherein the first compound may be included in the electron transport layer and the second compound may be included in the buffer layer.

In various embodiments, the buffer layer may directly contact the emission layer.

In various embodiments, the electron transport region may include, in addition to the first compound and/or the second compound, at least one compound selected from 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), Alq₃, BAlq, 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole (TAZ), and NTAZ.

A thickness of the buffer layer, the hole blocking layer, and the electron control layer may each independently be in a range of about 20 Å to about 1,000 Å, for example, about 30 Å to about 300 Å. When the thicknesses of the buffer layer, the hole blocking layer, and/or the electron control layer are within any of these ranges, the electron transport region may have excellent (or suitable) hole blocking characteristics or electron control characteristics without a substantial increase in driving voltage.

A thickness of the electron transport layer may be in a range of about 100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å. When the thickness of the electron transport layer is within any of the ranges described above, the electron transport layer may have satisfactory (or suitable) electron transport characteristics without a substantial increase in driving voltage.

The electron transport region (e.g., the electron transport layer in the electron transport region) may further include, in addition to the materials described above, a metal-containing material.

The metal-containing material may include at least one selected from an alkaline metal complex and an alkaline earth-metal complex. The alkaline metal complex may include a metal ion selected from a Li ion, a Na ion, a K ion, a Rb ion, and a Cs ion; and the alkaline earth-metal complex may include a metal ion selected from a Be ion, a Mg ion, a Ca ion, a Sr ion, and a Ba ion. A ligand coordinated with the metal ion of the alkaline metal complex or the alkaline earth-metal complex may each independently be selected from a hydroxy quinoline, a hydroxy isoquinoline, a hydroxy benzoquinoline, a hydroxy acridine, a hydroxy phenanthridine, a hydroxy phenylan oxazole, a hydroxy phenylthiazole, a hydroxy diphenylan oxadiazole, a hydroxy diphenylthiadiazole, a hydroxy phenylpyridine, a hydroxy phenylbenzimidazole, a hydroxy phenylbenzothiazole, a bipyridine, a phenanthroline, and a cyclopentadiene, but is not limited thereto.

For example, the metal-containing material may include a Li complex. The Li complex may include, for example, Compound ET-D1 (lithium quinolate, LiQ) and/or Compound ET-D2.

The electron transport region may include an electron injection layer that facilitates injection of electrons from the second electrode 190. The electron injection layer may directly contact the second electrode 190.

The electron injection layer may have i) a single-layered structure having a single layer including a single material, ii) a single-layered structure having a single layer including a plurality of different materials, or iii) a multi-layered structure having a plurality of layers including a plurality of different materials.

The electron injection layer may include an alkaline metal, an alkaline earth metal, a rare-earth-metal, an alkaline metal compound, an alkaline earth-metal compound, a rare-earth metal compound, an alkaline metal complex, an alkaline earth-metal complex, a rare-earth metal complex, or a combination thereof.

In various embodiments, the electron injection layer may include Li, Na, K, Rb, Cs, Mg, Ca, Er, Tm, Yb or any combination thereof. However, a material included in the electron injection layer is not limited thereto.

The alkaline metal may be selected from Li, Na, K, Rb, and Cs. In various embodiments, the alkaline metal may be Li, Na, or Cs. In various embodiments, the alkaline metal may be Li or Cs, but is not limited thereto.

The alkaline earth metal may be selected from Mg, Ca, Sr, and Ba.

The rare-earth metal may be selected from Sc, Y, Ce, Tb, Yb, Gd, and Tb.

The alkaline metal compound, the alkaline earth-metal compound, and the rare-earth metal compound may be selected from oxides and halides (e.g., fluorides, chlorides, bromides, and/or iodines) of the alkaline metal, the alkaline earth-metal, and the rare-earth metal, respectively.

For example, the alkaline metal compound may be selected from alkaline metal oxides (such as Li₂O, Cs₂O, and/or K₂O), and alkaline metal halides (such as LiF, NaF, CsF, KF, LiI, NaI, CsI, and/or KI). In various embodiments, the alkaline metal compound may be selected from LiF, Li₂O, NaF, LiI, NaI, CsI, and KI, but is not limited thereto.

The alkaline earth-metal compound may be selected from alkaline earth-metal compounds, such as BaO, SrO, CaO, Ba_(x)Sr_(1-x)O(0<x<1), and/or Ba_(x)Ca_(1-x)O(0<x<1). In various embodiments, the alkaline earth-metal compound may be selected from BaO, SrO, and CaO, but is not limited thereto.

The rare-earth metal compound may be selected from YbF₃, ScF₃, ScO₃, Y₂O₃, Ce₂O₃, GdF₃, and TbF₃. In various embodiments, the rare-earth metal compound may be selected from YbF₃, ScF₃, TbF₃, YbI₃, ScI₃, and TbI₃, but is not limited thereto.

The alkaline metal complex, the alkaline earth-metal complex, and the rare-earth metal complex may include an ion of an alkaline metal, an alkaline earth-metal, and a rare-earth metal, respectively, as described above; and a ligand coordinated with the metal ion of the alkaline metal complex, the alkaline earth-metal complex, and the rare-earth metal complex may each independently be selected from a hydroxy quinoline, a hydroxy isoquinoline, a hydroxy benzoquinoline, a hydroxy acridine, a hydroxy phenanthridine, a hydroxy phenylan oxazole, a hydroxy phenylthiazole, a hydroxy diphenylan oxadiazole, a hydroxy diphenylthiadiazole, a hydroxy phenylpyridine, a hydroxy phenylbenzimidazole, a hydroxy phenylbenzothiazole, a bipyridine, a phenanthroline, and a cyclopentadiene, but is not limited thereto.

The electron injection layer may consist of an alkaline metal, an alkaline earth metal, a rare-earth-metal, an alkaline metal compound, an alkaline earth-metal compound, a rare-earth metal compound, an alkaline metal complex, an alkaline earth-metal complex, a rare-earth metal complex, or a combination thereof, as described above. In various embodiments, the electron injection layer may further include an organic material. When the electron injection layer further includes an organic material, an alkaline metal, an alkaline earth metal, a rare-earth-metal, an alkaline metal compound, an alkaline earth-metal compound, a rare-earth metal compound, an alkaline metal complex, an alkaline earth-metal complex, a rare-earth metal complex, or a combination thereof may be homogeneously or non-homogeneously dispersed in a matrix including the organic material.

A thickness of the electron injection layer may be in a range of about 1 Å to about 100 Å, for example, about 3 Å to about 90 Å. When the thickness of the electron injection layer is within any of the ranges described above, the electron injection layer may have satisfactory (or suitable) electron injection characteristics without a substantial increase in driving voltage.

In various embodiments, the electron transport region of the organic light-emitting device 10 may include a buffer layer, an electron transport layer, and an electron injection layer, and

at least one layer selected from the electron transport layer and the electron injection layer may include an alkaline metal, an alkaline earth metal, a rare-earth-metal, an alkaline metal compound, an alkaline earth-metal compound, a rare-earth metal compound, an alkaline metal complex, an alkaline earth-metal complex, a rare-earth metal complex, or combinations thereof.

[Second Electrode 190]

The second electrode 190 may be disposed (e.g., positioned) on the organic layer 150 having the structure according to embodiments of the present disclosure. The second electrode 190 may be a cathode (which is an electron injection electrode), and in this regard, a material for forming the second electrode 190 may be selected from a metal, an alloy, an electrically conductive compound, and a mixture thereof, which have a relatively low work function.

The second electrode 190 may include at least one selected from lithium (Li), silver (Ag), magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), ITO, and IZO, but is not limited thereto. The second electrode 190 may be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode.

The second electrode 190 may have a single-layered structure, or a multi-layered structure including two or more layers.

[Description of FIGS. 2 to 6 ]

FIG. 2 is a schematic view of an organic light-emitting device 20 according to an embodiment. The organic light-emitting device 20 includes a first capping layer 210, the first electrode 110, the organic layer 150, and the second electrode 190, which are sequentially stacked in this stated order. FIG. 3 is a schematic view of an organic light-emitting device 30 according to an embodiment. The organic light-emitting device 30 includes the first electrode 110, the organic layer 150, the second electrode 190, and a second capping layer 220, which are sequentially stacked in this stated order. FIG. 4 is a schematic view of an organic light-emitting device 40 according to an embodiment. The organic light-emitting device 40 includes the first capping layer 210, the first electrode 110, the organic layer 150, the second electrode 190, and the second capping layer 220, which are sequentially stacked in this stated order.

Regarding FIGS. 2 to 4 , descriptions of the first electrode 110, the organic layer 150, and the second electrode 190 may each independently be understood by referring to the descriptions thereof presented in connection with FIG. 1 .

In the organic layer 150 of each of the organic light-emitting devices 20 and 40, light generated in an emission layer may pass through the first electrode 110, which may be a semi-transmissive electrode or a transmissive electrode, and the first capping layer 210 toward the outside; and in the organic layer 150 of each of the organic light-emitting devices 30 and 40, light generated in an emission layer may pass through the second electrode 190, which may be a semi-transmissive electrode ora transmissive electrode, and the second capping layer 220 toward the outside.

The first capping layer 210 and the second capping layer 220 may increase external luminescent efficiency according to the principle of constructive interference.

The first capping layer 210 and the second capping layer 220 may each independently be an organic capping layer including an organic material, an inorganic capping layer including an inorganic material, or a composite capping layer including an organic material and an inorganic material.

At least one selected from the first capping layer 210 and the second capping layer 220 may each independently include at least one material selected from carbocyclic compounds, heterocyclic compounds, amine-based compounds, porphine derivatives, phthalocyanine derivatives, naphthalocyanine derivatives, alkaline metal complexes, and alkaline earth-based complexes. The carbocyclic compound, the heterocyclic compound, and the amine-based compound may be optionally substituted with a substituent containing at least one element selected from O, N, S, Se, Si, F, Cl, Br, and I. In various embodiments, at least one selected from the first capping layer 210 and the second capping layer 220 may each independently include an amine-based compound.

In various embodiments, at least one selected from the first capping layer 210 and the second capping layer 220 may each independently include the compound represented by Formula 201 or the compound represented by Formula 202.

In various embodiments, at least one selected from the first capping layer 210 and the second capping layer 220 may each independently include a compound selected from Compounds HT₂₈ to HT₃₃ and Compounds CP1 to CPS, but is not limited thereto:

FIG. 5 is a scheatic view of an organic light-emitting device 11 according to an embodiment. The organic light-emitting device 11 may include a first electrode 110, a hole injection layer 151, a hole transport layer 153, an emission layer 155, a buffer layer 156, an electron transport layer 157, an electron injection layer 159, and a second electrode 190, which are sequentially stacked in this stated order.

FIG. 6 is a schematic view of an organic light-emitting device 12 according to an embodiment. The organic light-emitting device 12 may include the first electrode 110, a hole injection layer 151, a hole transport layer 153, an emission auxiliary layer 154, an emission layer 155, an electron transport layer 157, an electron injection layer 159, and the second electrode 190, which are sequentially stacked in this stated order.

Descriptions of the layers constituting the organic light-emitting devices 11 and 12 illustrated in FIGS. 5 and 6 are the same as described herein.

Hereinbefore, the organic light-emitting device according to one or more embodiments of the present disclosure has been described in connection with FIGS. 1-6 . However, embodiments of the present disclosure are not limited thereto.

Layers constituting the hole transport region, the emission layer, and layers constituting the electron transport region may each independently be formed in a certain region by using one or more suitable methods such as vacuum deposition, spin coating, casting, langmuir-blodgett (LB) deposition, ink-jet printing, laser-printing, and/or laser-induced thermal imaging.

When layers constituting the hole transport region, the emission layer, and layers constituting the electron transport region are formed by vacuum deposition, for example, the vacuum deposition may be performed at a deposition temperature of about 100 to about 500° C., at a vacuum degree of about 10⁻⁸ to about 10⁻³ torr, and at a deposition rate of about 0.01 to about 100 Å/sec, by taking into account a compound to be included in a layer to be formed, and the structure of a layer to be formed.

When layers constituting the hole transport region, the emission layer, and layers constituting the electron transport region are formed by spin coating, for example, the spin coating may be performed at a coating speed of about 2,000 rpm to about 5,000 rpm and at a heat treatment temperature of about 80° C. to 200° C., by taking into account a compound to be included in a layer to be formed, and the structure of a layer to be formed.

[General Definition of Substituents]

The term “C₁-C₆₀ alkyl group,” as used herein, may refer to a linear or branched aliphatic saturated hydrocarbon monovalent group having 1 to 60 carbon atoms, and non-limiting examples thereof include a methyl group, an ethyl group, a propyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an iso-amyl group, and a hexyl group. The term “C₁-C₆₀ alkylene group,” as used herein, may refer to a divalent group having the same structure as the C₁-C₆₀ alkyl group.

The term “C₂-C₆₀ alkenyl group,” as used herein, may refer to a hydrocarbon group having at least one carbon-carbon double bond at one or more positions along the hydrocarbon chain of the C₂-C₆₀ alkyl group (e.g, in the middle and/or at the terminus of the C₂-C₆₀ alkyl group), and non-limiting examples thereof include an ethenyl group, a propenyl group, and a butenyl group. The term “C₂-C₆₀ alkenylene group,” as used herein, may refer to a divalent group having the same structure as the C₂-C₆₀ alkenyl group.

The term “C₂-C₆₀ alkynyl group,” as used herein, may refer to a hydrocarbon group having at least one carbon-carbon triple bond at one or more positions along the hydrocarbon chain of the C₂-C₆₀ alkyl group (e.g, in the middle and/or at the terminus of the C₂-C₆₀ alkyl group), and non-limiting examples thereof include an ethynyl group and a propynyl group. The term “C₂-C₆₀ alkynylene group,” as used herein, may refer to a divalent group having the same structure as the C₂-C₆₀ alkynyl group.

The term “C₁-C₆₀ alkoxy group,” as used herein, may refer to a monovalent group represented by —OA₁₀₁ (wherein A₁₀₁ is the C₁-C₆₀ alkyl group), and non-limiting examples thereof include a methoxy group, an ethoxy group, and an isopropoxy group.

The term “C₃-C₁₀ cycloalkyl group,” as used herein, may refer to a monovalent saturated hydrocarbon monocyclic group having 3 to 10 carbon atoms, and non-limiting examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group. The term “C₃-C₁₀ cycloalkylene group,” as used herein, may refer to a divalent group having the same structure as the C₃-C₁₀ cycloalkyl group.

The term “C₁-C₁₀ heterocycloalkyl group,” as used herein, may refer to a monovalent monocyclic group having at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom, and 1 to 10 carbon atoms, and non-limiting examples thereof include 1,2,3,4-oxatriazolidinyl group, a tetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkylene group,” as used herein, may refer to a divalent group having the same structure as the C₁-C₁₀ heterocycloalkyl group.

The term “C₃-C₁₀ cycloalkenyl group,” as used herein, may refer to a monovalent monocyclic group that has 3 to 10 carbon atoms and at least one carbon-carbon double bond in the ring thereof and does not have aromaticity, and non-limiting examples thereof include a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenyl group. The term “C₃-C₁₀ cycloalkenylene group,” as used herein, may refer to a divalent group having the same structure as the C₃-C₁₀ cycloalkenyl group.

The term “C₁-C₁₀ heterocycloalkenyl group,” as used herein, may refer to a monovalent monocyclic group that has at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom, 1 to 10 carbon atoms, and at least one double bond in its ring. Non-limiting examples of the C₁-C₁₀ heterocycloalkenyl group inlclude a 4,5-dihydro-1,2,3,4-oxatriazolyl group, a 2,3-dihydrofuranyl group, and a 2,3-dihydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkenylene group,” as used herein, may refer to a divalent group having the same structure as the C₁-C₁₀ heterocycloalkenyl group.

The term “C₆-C₆₀ aryl group,” as used herein, may refer to a monovalent group having an aromatic system having 6 to 60 carbon atoms, and the term “C₆-C₆₀ arylene group,” as used herein, may refer to a divalent group having an aromatic system having 6 to 60 carbon atoms. Non-limiting examples of the C₆-C₆₀ aryl group include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, and a chrysenyl group. When the C₆-C₆₀ aryl group and the C₆-C₆₀ arylene group each independently include two or more rings, the respective rings may be condensed (e.g., fused) with each other.

The term “C₁-C₆₀ heteroaryl group,” as used herein, may refer to a monovalent group having a heterocyclic aromatic system that has at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom, and 1 to 60 carbon atoms. The term “C₁-C₆₀ heteroarylene group,” as used herein, may refer to a divalent group having a heterocyclic aromatic system that has at least one heteroatom selected from N, O, P, and S as a ring-forming atom, and 1 to 60 carbon atoms. Non-limiting examples of the C₁-C₆₀ heteroaryl group include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, and an isoquinolinyl group. When the C₁-C₆₀ heteroaryl group and the C₁-C₆₀ heteroarylene group each independently include two or more rings, the respective rings may be condensed (e.g., fused) with each other.

The term “C₆-C₆₀ aryloxy group,” as used herein, may refer to a monovalent group represented by —OA₁₀₂ (wherein A₁₀₂ is the C₆-C₆₀ aryl group), and the term “C₆-C₆₀ arylthio group,” as used herein, may refer to a monovalent group represented by —SA₁₀₃ (wherein A₁₀₃ is the C₆-C₆₀ aryl group).

The term “monovalent non-aromatic condensed polycyclic group,” as used herein, may refer to a monovalent group that has two or more rings condensed (e.g., fused) with each other, only carbon atoms as ring-forming atoms (e.g., 8 to 60 carbon atoms), and non-aromaticity in the entire molecular structure (e.g., does not have overall aromaticity). Non-limiting example of the monovalent non-aromatic condensed polycyclic group include a fluorenyl group. The term “divalent non-aromatic condensed polycyclic group,” as used herein, may refer to a divalent group having the same structure as the monovalent non-aromatic condensed polycyclic group.

The term “monovalent non-aromatic condensed heteropolycyclic group,” as used herein, may refer to a monovalent group that has two or more rings condensed (e.g., fused) to each other, has at least one heteroatom selected from N, O, Si, P, and S, other than carbon atoms (e.g., 1 to 60 carbon atoms), as a ring-forming atom, and has non-aromaticity in the entire molecular structure (e.g., does not have overall aromaticity). Non-limiting example of the monovalent non-aromatic condensed heteropolycyclic group include a carbazolyl group. The term “divalent non-aromatic condensed heteropolycyclic group,” as used herein, may refer to a divalent group having the same structure as the monovalent non-aromatic condensed heteropolycyclic group.

The term “C₅-C₆₀ carbocyclic group,” as used herein, may refer to a monocyclic or polycyclic group having 5 to 60 carbon atoms in which ring-forming atoms are carbon atoms only. The term “C₅-C₆₀ carbocyclic group,” as used herein, may refer to an aromatic carbocyclic group or a non-aromatic carbocyclic group. The term “C₅-C₆₀ carbocyclic group,” as used herein, may refer to a ring (such as a benzene ring), a monovalent group (such as a phenyl group), or a divalent group (such as a phenylene group). In various embodiments, depending on the number of substituents connected to the C₅-C₆₀ carbocyclic group, the C₅-C₆₀ carbocyclic group may be a trivalent group or a quadrivalent group.

The term “C₁-C₆₀ heterocyclic group,” as used herein, may refer to a group having the same structure as the C₁-C₆₀ carbocyclic group, except that as a ring-forming atom, at least one heteroatom selected from N, O, Si, P, and S is used, in addition to carbon atoms (e.g., the number of carbon atoms may be in a range of 1 to 60).

At least one substituent of the substituted C₅-C₆₀ carbocyclic group, the substituted C₁-C₆₀ heterocyclic group, the substituted C₃-C₁₀ cycloalkylene group, the substituted C₁-C₁₀ heterocycloalkylene group, the substituted C₃-C₁₀ cycloalkenylene group, the substituted C₁-C₁₀ heterocycloalkenylene group, the substituted C₆-C₆₀ arylene group, the substituted C₁-C₆₀ heteroarylene group, the substituted divalent non-aromatic condensed polycyclic group, the substituted divalent non-aromatic condensed heteropolycyclic group, the substituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group may be selected from the group consisting of:

deuterium (-D), —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂);

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂); and

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryl group substituted with a C₁-C₆₀ alkyl group, a C₆-C₆₀ aryl group substituted with a C₆-C₆₀ aryl group, a terphenyl group, a C₁-C₆₀ heteroaryl group, a C₁-C₆₀ heteroaryl group substituted with a C₁-C₆₀ alkyl group, a C₁-C₆₀ heteroaryl group substituted with a C₆-C₆₀ aryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group.

The term “Ph” as used herein may refer to a phenyl group, the term “Me” as used herein may refer to a methyl group, the term “Et” as used herein may refer an ethyl group, the term “ter-Bu” or “Bu^(t)” as used herein, may refer a tert-butyl group, the term “OMe” as used herein may refer to a methoxy group, and “D” as used herein may refer to deuterium.

The term “a biphenyl group” as used herein may refer to a monovalent group having two benzene rings linked to each other via a single bond. The “biphenyl group” may be referred to as a “phenyl group substituted with a phenyl group. The “biphenyl group” may also be referred to as a “substituted phenyl group” having a “C₆-C₆₀ aryl group” as a substituent.

The term “a terphenyl group” as used herein may refer to a monovalent group having three benzene rings in which adjacent benzenes are linked to each other via a single bond. The “terphenyl group” may be referred to as a “phenyl group substituted with a biphenyl group. The “terphenyl group” may also be referred to as a “substituted phenyl group” having a “C₆-C₆₀ aryl group substituted with a C₆-C₆₀ aryl group” as a substituent.

*and *′, as used herein, unless defined otherwise, each independently refer to a binding site to a neighboring atom in a corresponding formula.

Hereinafter, a compound according to embodiments of the present disclosure and an organic light-emitting device according to embodiments will be described in more detail with reference to Synthesis Examples and Examples. However, these examples are provided for illustrative purposes only, and should not in any sense be interpreted as limiting the scope of the present disclosure. The expression “B was used instead of A” used in describing Synthesis Examples may refer to an identical (or substantially the same) number of molar equivalents of A being used in place of molar equivalents of B.

EXAMPLES Example 1

An anode was prepared by cutting an ITO glass substrate (manufactured by Corning Inc.), on which ITO was formed to a thickness of 15 Ω/cm² (1,200 Å), to a size of 50 mm×50 mm×0.7 mm, ultrasonically cleaning the ITO glass substrate (anode) using isopropyl alcohol and pure water, each for 5 minutes, and then, exposing the ITO glass substrate to irradiation of UV light for 30 minutes and ozone. Then, the ITO glass substrate was loaded into a vacuum deposition apparatus.

m-MTDATA was vacuum-deposited on the ITO glass substrate (anode) to form a hole injection layer having a thickness of 700 Å. Then, NPB was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 100 Å.

ADN (as a host) and FBD (as a dopant) were co-deposited on the hole transport layer at a weight ratio of 95:5 to form an emission layer having a thickness of 300 Å.

Compound 2-48 was deposited on the emission layer to form a buffer layer having a thickness of 100 Å, and then, Compound 1-3 was deposited on the buffer layer to form an electron transport layer having a thickness of 200 Å. LiF was deposited on the electron transport layer to form an electron injection layer having a thickness of 10 Å. Al was vacuum-deposited on the electron injection layer to form a cathode having a thickness of 2,000 Å, thereby completing the manufacture of an organic light-emitting device.

Examples 2 to 27 and Comparative Examples 1 and 4

Organic light-emitting devices were manufactured in the same (or substantially the same) manner as in Example 1, except that compounds as shown in Table 5 were respectively used instead of Compounds 2-48 and 1-3 in forming a buffer layer and an electron transport layer.

Evaluation Example 1

The driving voltage and efficiency of the organic light-emitting devices of Examples 1 to 27 and Comparative Examples 1 to 4 were evaluated by using a Keithley SMU 236 meter. Results thereof are shown in Table 5.

TABLE 5 Electron Driving transport layer voltage Efficiency Buffer layer (weight ratio) (V) (cd/A) Example 1 Compound Compound 1-3 4.5 4.8 2-48 Example 2 Compound Compound 1-5 4.4 4.9 2-48 Example 3 Compound Compound 1-8 4.4 5.1 2-58 Example 4 Compound Compound 1-8 4.4 5.2 2-190 Example 5 Compound Compound 1-10 4.3 5.1 2-162 Example 6 Compound Compound 1-17 4.5 5.0 2-48 Example 7 Compound Compound 1-25 4.6 5.1 2-147a Example 8 Compound Compound 4.5 5.0 2-147a 1-25:Li (98:2) Example 9 Compound Compound 1-53 4.6 5.0 2-162 Example 10 Compound Compound 1-32 4.5 5.1 2-48 Example 11 Compound Compound 1-32 4.4 4.9 2-190 Example 12 Compound Compound 4.3 5.1 2-190 1-32:LiQ (5:5) Example 13 Compound Compound 1-37 4.5 4.9 2-136a Example 14 Compound Compound 1-37 4.5 5.0 2-190 Example 15 Compound Compound 4.5 5.0 2-136a 1-37:LiQ (5:5) Example 16 Compound Compound 1-46 4.5 4.9 2-147a Example 17 Compound Compound 1-46 4.6 5.1 2-162 Example 18 Compound Compound 4.3 5.0 2-147a 1-46:LiQ (5:5) Example19 Compound Compound 1-33 4.4 4.9 2-48 Example20 Compound Compound 1-33 4.3 5.1 2-190 Example 21 Compound Compound 4.3 5.0 2-48 1-33:LiQ (5:5) Example 22 Compound Compound 1-43 4.4 5.0 2-136a Example 23 Compound Compound 1-43 4.3 4.9 2-64 Example 24 Compound Compound 4.4 5.1 2-136a 1-43:LiQ (5:5) Example 25 Compound Compound 1-51 4.3 4.9 2-147a Example 26 Compound Compound 1-51 4.4 5.0 2-58 Example 27 Compound Compound 4.3 5.1 2-58 1-51:LiQ (5:5) Comparative Alq₃ 4.9 4.4 Example 1 Comparative Compound 1-32 4.6 4.6 Example 2 Comparative Compound Alq₃ 4.7 4.5 Example 3 2-48 Comparative Compound Alq₃ 4.7 4.5 Example 4 2-190

Referring to the results shown in Table 5, it can be seen that the organic light-emitting devices of Examples 1 to 27 had a low driving voltage and high efficiency, compared to those of the organic light-emitting devices of Comparative Examples 1 to 4.

Example 28

An anode was prepared by cutting an ITO glass substrate (manufactured by Corning Inc.), on which ITO was formed to a thickness of 15 Ω/cm² (1,200 Å), to a size of 50 mm×50 mm×0.7 mm, ultrasonically cleaning the ITO glass substrate (anode) using isopropyl alcohol and pure water, each for 5 minutes, and then, exposing the ITO glass substrate to irradiation of UV light for 30 minutes and ozone. Then, the resulting ITO glass substrate was loaded into a vacuum deposition apparatus.

m-MTDATA was vacuum-deposited on the ITO glass substrate (anode) to form a hole injection layer having a thickness of 700 Å. Then, TCTA was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 100 Å.

CBP (as a host) and Ir(ppy)₃ (as a dopant) were co-deposited on the hole transport layer at a weight ratio of 90:10 to form an emission layer having a thickness of 300 Å.

Compound 2-136a was deposited on the emission layer to form a buffer layer having a thickness of 100 Å, and then, Compound 1-5 was deposited on the buffer layer to form an electron transport layer having a thickness of 200 Å. LiF was deposited on the electron transport layer to form an electron injection layer having a thickness of 10 Å. Al was vacuum-deposited on the electron injection layer to form a cathode having a thickness of 2,000 Å, thereby completing the manufacture of an organic light-emitting device.

Examples 29 to 46 and Comparative Examples 5 to 8

Organic light-emitting devices were manufactured in the same (or substantially the same) manner as in Example 28, except that compounds listed in Table 6 were respectively used instead of Compounds 2-136a and 1-5 in forming a buffer layer and an electron transport layer.

Evaluation Example 2

The driving voltage and efficiency of the organic light-emitting devices of Examples 28 to 46 and Comparative Examples 5 to 8 were evaluated by using a Keithley SMU 236 meter. Results thereof are shown in Table 6.

TABLE 6 Electron transport layer Driving Efficiency Buffer layer (weight ratio) voltage (V) (cd/A) Example 28 Compound Compound 1-5 5.7 39.3 2-136a Example 29 Compound Compound 1-8 5.6 40.1 2-64 Example 30 Compound Compound 1-8 5.6 41.0 2-190 Example 31 Compound Compound 5.7 41.5 2-162 1-10 Example 32 Compound Compound 5.7 42.0 2-136a 1-25 Example 33 Compound Compound 5.6 42.0 2-147a 1-32 Example 34 Compound Compound 5.7 41.3 2-162 1-32 Example 35 Compound Compound 5.6 40.0 2-136a 1-37 Example 36 Compound Compound 5.6 40.5 2-190 1-37 Example 37 Compound Compound 5.5 40.5 2-58 1-46 Example 38 Compound Compound 5.6 42.3 2-162 1-46 Example 39 Compound Compound 5.5 41.5 2-58 1-46:LiQ (5:5) Example 40 Compound Compound 5.6 41.0 2-64 1-33 Example 41 Compound Compound 5.5 40.5 2-190 1-33 Example 42 Compound Compound 5.5 42.0 2-64 1-33:LiQ (5:5) Example 43 Compound Compound 5.6 40.7 2-147a 1-43 Example 44 Compound Compound 5.5 41.3 2-58 1-43 Example 45 Compound Compound 5.6 40.5 2-48 1-51 Example 46 Compound Compound 5.5 41.2 2-136a 1-51 Comparative BAlq Alq₃ 6.1 36.1 Example 5 Comparative BAlq Compound 5.9 39.0 Example 6 1-32 Comparative Compound Alq₃ 6.0 38.0 Example7 2-48 Comparative Compound Alq₃ 5.9 37.3 Example8 2-190

Referring to the results shown in Table 6, it can be seen that that the organic light-emitting devices of Examples 28 to 46 had a low driving voltage and high efficiency, compared to those of the organic light-emitting devices of Comparative Examples 5 to 8.

Example 47

An anode was prepared by cutting an ITO glass substrate (manufactured by Corning Inc.), on which ITO was formed to a thickness of 15 Ω/cm² (1,200 Å), to a size of 50 mm×50 mm×0.7 mm, ultrasonically cleaning the ITO glass substrate (anode) using isopropyl alcohol and pure water, each for 5 minutes, and then, exposing the ITO glass substrate to irradiation of UV light for 30 minutes and ozone. Then, the resulting ITO glass substrate was loaded into a vacuum deposition apparatus.

m-MTDATA was vacuum-deposited on the ITO glass substrate (anode) to form a hole injection layer having a thickness of 700 Å. Then, TCTA was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 100 Å.

CBP (as a host) and Ir(bzq)₃ (as a dopant) were co-deposited on the hole transport layer at a weight ratio of 96:4 to form an emission layer having a thickness of 300 Å.

Compound 2-147a was deposited on the emission layer to form a buffer layer having a thickness of 100 Å, and then, Compound 1-8 was deposited on the buffer layer to form an electron transport layer having a thickness of 200 Å. LiF was deposited on the electron transport layer to form an electron injection layer having a thickness of 10 Å. Al was vacuum-deposited on the electron injection layer to form a cathode having a thickness of 2,000 Å, thereby completing the manufacture of an organic light-emitting device.

Examples 48 to 66 and Comparative Examples 9 to 12

Organic light-emitting devices were manufactured in the same (or substantially the same) manner as in Example 47, except that compounds listed in Table 7 were respectively used instead of Compounds 2-147a and 1-8 in forming a buffer layer and an electron transport layer.

Evaluation Example 3

The driving voltage and efficiency of the organic light-emitting devices of Examples 47 to 66 and Comparative Examples 9 to 12 were evaluated by using a Keithley SMU 236 meter. Results thereof are shown in Table 7.

TABLE 7 Electron transport layer Driving Efficiency Buffer layer (weight ratio) voltage (V) (cd/A) Examle 47 Compound Compound 5.9 24.5 2-147a 1-8 Example 48 Compound Compound 5.7 24.7 2-162 1-8 Example 49 Compound Compound 5.8 23.8 2-190 1-10 Example 50 Compound Compound 5.7 25.0 2-162 1-25 Example 51 Compound Compound 5.6 24.5 2-48 1-32 Example 52 Compound Compound 5.7 23.9 2-136a 1-32 Example 53 Compound Compound 5.6 24.8 2-136a 1-32:LiQ (5:5) Example 54 Compound Compound 5.7 24.0 2-147a 1-37 Example 55 Compound Compound 5.6 24.2 2-190 1-37 Example 56 Compound Compound 5.7 24.0 2-147a 1-46 Example 57 Compound Compound 5.7 23.8 2-190 1-46 Example 58 Compound Compound 5.6 24.2 2-190 1-46:LiQ (5:5) Example 59 Compound Compound 5.6 24.5 2-58 1-33 Example 60 Compound Compound 5.6 24.1 2-162 1-33 Example 61 Compound Compound 5.7 24.0 2-162 1-33:LiQ (5:5) Example 62 Compound Compound 5.8 24.5 2-136a 1-43 Example63 Compound Compound 5.7 23.5 2-162 1-43 Example64 Compound Compound 5.8 24.3 2-48 1-51 Example65 Compound Compound 5.7 24.0 2-64 1-51 Example66 Compound Compound 5.6 24.3 2-64 1-51:LiQ (5:5) Comparative BAlq Alq₃ 6.2 21.6 Example9 Comparative BAlq Compound 6.0 23.0 Example10 1-32 Comparative Compound Alq₃ 6.1 23.1 Example11 2-48 Comparative Compound Alq₃ 6.0 23.3 Example12 2-190

Referring to the results shown in Table 7, it can be seen that the organic light-emitting devices of Examples 47 to 66 had a low driving voltage and high efficiency, compared to those of the organic light-emitting devices of Comparative Examples 9 to 12.

Example 67

An anode was prepared by cutting an ITO glass substrate (manufactured by Corning Inc.), on which ITO was formed to a thickness of 15 Ω/cm² (1,200 Å), to a size of 50 mm×50 mm×0.7 mm, ultrasonically cleaning the ITO glass substrate (anode) using isopropyl alcohol and pure water, each for 5 minutes, and then, exposing the ITO glass substrate to irradiation of UV light for 30 minutes and ozone to clean. Then, the resulting ITO glass substrate was loaded into a vacuum deposition apparatus.

m-MTDATA was vacuum-deposited on the ITO glass substrate (anode) to form a hole injection layer having a thickness of 700 Å. Then, TCTA was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 100 Å.

CBP (as a host) and Ir(pq)₂(acac) (as a dopant) were co-deposited on the hole transport layer at a weight ratio of 96:4 to form an emission layer having a thickness of 300 Å.

Compound 2-48 was deposited on the emission layer to form a buffer layer having a thickness of 100 Å, and then, Compound 1-37 was deposited on the buffer layer to form an electron transport layer having a thickness of 200 Å. LiF was deposited on the electron transport layer to form an electron injection layer having a thickness of 10 Å. Al was vacuum-deposited on the electron injection layer to form a cathode having a thickness of 2,000 Å, thereby completing the manufacture of an organic light-emitting device.

Comparative Example 13

An organic light-emitting device was manufactured in the same (or substantially the same) manner as in Example 67, except that compounds listed in Table 8 were respectively used instead of Compounds 2-48 and 1-13 in forming a buffer layer and an electron transport layer.

Evaluation Example 4

The driving voltage and efficiency of the organic light-emitting devices of Example 67 and Comparative Example 13 were evaluated by using a Keithley SMU 236 meter. Results thereof are shown in Table 8.

TABLE 8 Electron transport Driving Efficiency Buffer layer layer voltage (V) (cd/A) Example 67 Compound Compound 5.6 29.1 2-48 1-37 Comparative BAlq Alq₃ 6.2 25.4 Example 13

Referring to the results shown in Table 8, it can be seen that the organic light-emitting device of Example 67 had a low driving voltage and high efficiency, compared to those of the organic light-emitting device of Comparative Example 13.

According to one or more embodiments, an organic light-emitting device may have a low driving voltage and high efficiency.

As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one selected from,” “one selected from,” “selected from,” “at least one of,” and “one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. Further, the use of “may” when describing embodiments of the present invention refers to “one or more embodiments of the present invention.”

As used herein, the terms “use,” “using,” and “used” may be considered synonymous with the terms “utilize,” “utilizing,” and “utilized,” respectively.

In addition, as used herein, the terms “substantially,” “about,” and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent deviations in measured or calculated values that would be recognized by those of ordinary skill in the art.

It will be understood that when an element such as a layer, film, region, or substrate is referred to as being “on” another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” or “directly contacting” another element, there are no intervening elements present.

Also, any numerical range recited herein is intended to include all sub-ranges of the same numerical precision subsumed within the recited range. For example, a range of “1.0 to 10.0” is intended to include all subranges between (and including) the recited minimum value of 1.0 and the recited maximum value of 10.0, that is, having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as, for example, 2.4 to 7.6. Any maximum numerical limitation recited herein is intended to include all lower numerical limitations subsumed therein and any minimum numerical limitation recited in this specification is intended to include all higher numerical limitations subsumed therein. Accordingly, Applicant reserves the right to amend this specification, including the claims, to expressly recite any sub-range subsumed within the ranges expressly recited herein.

It should be understood that embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments.

While one or more embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined by the following claims and equivalents thereof. 

What is claimed is:
 1. An organic light-emitting device comprising: a first electrode; a second electrode facing the first electrode; an emission layer between the first electrode and the second electrode; a hole transport region between the first electrode and the emission layer; and an electron transport region between the emission layer and the second electrode, wherein the electron transport region comprises a first compound, at least one selected from the hole transport region and the electron transport region comprises a second compound, the first compound is represented by one selected from Formulae 1A to 1D or the first compound is selected from Compounds 1-2, 1-4, 1-7, 1-9 to 1-11, 1-22, 1-26, 1-29, 1-58, 1-59, 1-70 to 1-75, 1-88 to 1-90, 1-94 to 1-96, 1-101, 1-102, 1-106, 1-107, 1-111, 1-135, 1-143, 1-145, 1-146, 1-148, 1-175, 1-177, 1-225, 1-226, 1-229, 1-252 and 1-256, and the second compound is represented by Formula 2A or Formula 2B:

wherein, in Formulae 1A to 1D, 2A, and 2B, ring A₁ is a C₅-C₆₀ carbocyclic group or a C₁-C₃₀ heterocyclic group, each substituted with at least one *-[(L₁₁)_(a11)-(R₁₁)_(b11)], and ring A₂ is a C₅-C₆₀ carbocyclic group or a C₁-C₃₀ heterocyclic group, each substituted with at least one *-[(L₁₂)_(a12)-(R₁₂)_(b12)], rings A₂₁, A₂₂, and A₂₃ in Formula 2A are each independently selected from groups represented by Formulae 2-1 to 2-36, each substituted with at least one *-[(L₂₂)_(a22)-(R₂₂)_(b22)], and at least two of rings A₂₁, A₂₂ and A₂₃ in Formula 2A are each independently selected from groups represented by Formulae 2-1 to 2-3, 2-8 to 2-27 and 2-29 to 2-36, each substituted with at least one *-[(L₂₂)_(a22)-(R₂₂)_(b22)], rings A₂₁ and A₂₃ in Formula 2B are each independently selected from groups represented by Formulae 2-1 to 2-3, 2-8 to 2-27 and 2-29 to 2-36, each substituted with at least one *-[(L₂₂)_(a22)-(R₂₂)_(b22)]:

wherein, in Formulae 2-1 to 2-36, X₂₂ and X₂₃ are each independently O, S, or Se, or are each independently a moiety comprising C, N, or Si, T₂₁ to T₂₈ are each independently N, or are each independently a moiety comprising C, T₁ to T₄ are each independently carbon or nitrogen, wherein a bond between T₁ and T₂ is a single bond, and a bond between T₃ and T₄ is a double bond, ring A₁ is condensed with a 5-membered ring in Formulae 1B and 1D, while sharing T₁ and T₂ therewith, and ring A₂ is condensed with a 5-membered ring in Formulae 1C and 1D, while sharing T₃ and T₄ therewith, T₁₁ and T₁₂ are each independently carbon or nitrogen, T₁₃ is N or C(R₂₇), and T₁₄ is N or C(R₂₈), wherein two or more selected from three T₁₁(s) in Formula 2A are identical to or different from each other, two or more selected from three T₁₂(s) in Formula 2A are identical to or different from each other, two T₁₁(s) in Formula 2B are identical to or different from each other, two T₁₂(s) in Formula 2B are identical to or different from each other, T₁₁ and T₁₂ fused to ring A₂₂ of Formula 2A are both carbon, a bond between T₁₁ and T₁₂ is a single bond or a double bond, a case where three T₁₁(s) and three T₁₂(s) in Formula 2A are all nitrogen is excluded, and a case where two T₁₁(s), two T₁₂(s), T₁₃, and T₁₄ in Formula 2B are all nitrogen is excluded, rings A₂₁, A₂₂, and A₂₃ are each condensed with a 7-membered ring in each of Formulae 2A and 2B, while sharing T₁₁ and T₁₂ therewith, X₁ is selected from O, S, and N-[(L₁)_(a1)-(R₁)_(b1)], X₂ is N or C-(L₂)_(a2)-(R₂)_(b2), X₃ is N or C-(L₃)_(a3)-(R₃)_(b3), X₄ is N or C-(L₄)_(a4)-(R₄)_(b4), and X₅ is N or C-(L₅)_(a5)-(R₅)_(c5), provided that Formula 1C is not a benzimidazole or a purine, X₂₁ is selected from O, S, Se, C(R₂₃)(R₂₄), Si(R₂₃)(R₂₄), and N-[(L₂₁)_(a21)-(R₂₁)_(b21)], L₁ to L₅, L₁₁, L₁₂, L₂₁, and L₂₂ are each independently selected from a substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀ arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group, provided that L₁ to L₅, L₁₁, and L₁₂ each independently do not include an anthracenylene group, a1 to a5, a11, a12, a21, and a22 are each independently an integer selected from 0 to 5, R₁ to R₅, R₁₁, R₁₂, R₂₇, and R₂₈ are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂), provided that R₁ to R₅, R₁₁, and R₁₂ each independently do not include an anthracenyl group, R₂₁ to R₂₄ are each independently selected from groups represented by Formulae 5-1 to 5-49:

wherein in Formulae 5-1 to 5-49, Y₃₁ and Y₃₂ are each independently O, S, C(Z₃₃)(Z₃₄), N(Z₃₅), or Si(Z₃₆)(Z₃₇), Z₃₁ to Z₃₈ are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, a benzonaphthyridinyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, an azadibenzosilolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), and —P(═O)(Q₃₁)(Q₃₂), e₂ is an integer selected from 0 to 2, e₃ is an integer selected from 0 to 3, e₄ is an integer selected from 0 to 4, e₅ is an integer selected from 0 to 5, e₆ is an integer selected from 0 to 6, e₇ is an integer selected from 0 to 7, e₉ is an integer selected from 0 to 9, and * indicates a binding site to a neighboring atom, b1 to b5, b11, b12, b21, and b22 are each independently an integer selected from 0 to 4, R₄ and R₅ are optionally connected to each other to form a saturated or unsaturated ring, and at least one substituent of the substituted C₃-C₁₀ cycloalkylene group, the substituted C₁-C₁₀ heterocycloalkylene group, the substituted C₃-C₁₀ cycloalkenylene group, the substituted C₁-C₁₀ heterocycloalkenylene group, the substituted C₆-C₆₀ arylene group, the substituted C₁-C₆₀ heteroarylene group, the substituted divalent non-aromatic condensed polycyclic group, the substituted divalent non-aromatic condensed heteropolycyclic group, the substituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group is selected from the group consisting of: deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group; a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂); a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, and a terphenyl group; a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂); and —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), wherein Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryl group substituted with a C₁-C₆₀ alkyl group, a C₆-C₆₀ aryl group substituted with a C₆-C₆₀ aryl group, a terphenyl group, a C₁-C₆₀ heteroaryl group, a C₁-C₆₀ heteroaryl group substituted with a C₁-C₆₀ alkyl group, a C₁-C₆₀ heteroaryl group substituted with a C₆-C₆₀ aryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group,


2. The organic light-emitting device of claim 1, wherein in Formulae 1B to 1D, ring A₁ is selected from groups represented by Formulae 1-1 to 1-8, each substituted with at least one *-[(L₁₁)_(a11)-(R₁₁)_(b11)], and ring A₂ is selected from groups represented by Formulae 1-9 to 1-21, each substituted with at least one *-[(L₁₂)_(a12)-(R₁₂)_(b12)]:

wherein, in Formulae 1-1 to 1-21, descriptions of T₁ to T₄ are each independently the same as those provided in connection with Formulae 1B to 1D, X₁₁ and X₁₂ are each independently O or S, or are each independently a moiety comprising C, and T₃₁ to T₃₈ and T₄₁ to T₄₈ are each independently N or C, or are each independently a moiety comprising C.
 3. The organic light-emitting device of claim 1, wherein X₂₁ in Formulae 2A and 2B is N[(L₂₁)_(a21)-(R₂₁)_(b21)].
 4. The organic light-emitting device of claim 1, wherein i) in Formula 1A, X₁ is O, S, or N-[(L₁)_(a1)-(R₁)_(b1)], X₂ is C-(L₂)_(a2)-(R₂)_(b2), X₃ is N, X₄ is C-(L₄)-(R₄)_(b4), and X₅ is N, X₁ is O, S, or N-[(L₁)_(a1)-(R₁)_(b1)], X₂ is N, X₃ is C-(L₃)_(a3)-(R₃)_(b3), X₄ is C-(L₄)_(a4)-(R₄)_(b4), and X₅ is N, X₁ is N-[(L₁)_(a1)-(R₁)_(b1)], X₂ is C-(L₂)_(a2)-(R₂)_(b2), X₃ is C-(L₃)_(a3)-(R₃)_(b3), X₄ is N, and X₅ is N, X₁ is N-[(L₁)_(a1)-(R₁)_(b1)], X₂ is N, X₃ is C-(L₃)_(a3)-(R₃)_(b3), X₄ is N, and X₅ is C-(L₅)_(a5)-(R₅)_(b5), X₁ is N-[(L₁)_(a1)-(R₁)_(b1)], X₂ is C-(L₂)_(a2)-(R₂)_(b2), X₃ is C-(L₃)_(a3)-(R₃)_(b3), X₄ is C-(L₄)_(a4)-(R₄)_(b4), and X₅ is C-(L₅)_(a5)-(R₅)_(b5), or X₁ is N-[(L₁)_(a1)-(R₁)_(b1)], X₂ is C-(L₂)_(a2)-(R₂)_(b2), X₃ is N, X₄ is C-(L₄)_(a4)-(R₄)_(b4), and X₅ is C-(L₅)_(a5)-(R₅)_(b5), ii) in Formula 1B, T₁ is N, T₂ is C, X₂ is C-(L₂)_(a2)-(R₂)_(b2), X₃ is C-(L₃)_(a3)-(R₃)_(b3), and X₄ is N, or T₁ is N, T₂ is C, X₂ is C-(L₂)_(a2)-(R₂)_(b2), X₃ is N, and X₄ is N, iii) in the Formula 1C, X₁ is O, S, or N-[(L₁)_(a1)-(R₁)_(b1)], T₃ and T₄ are both C, X₄ is N, and X₅ is C-(L₅)_(a5)-(R₅)_(c5), provided that Formula 1C is not a benzimidazole or a purine, or iv) in Formula 1D, T₁ is N, T₂ is C, T₃ and T₄ is C, X₄ is N or C-(L₄)_(a4)-(R₄)_(b4).
 5. The organic light-emitting device of claim 1, wherein L₁ to L₅, L₁₁, L₁₂, L₂₁, and L₂₂ are each independently selected from the group consisting of: a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, a heptalenylene group, an indacenylene group, an acenaphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a spiro-benzofluorene-fluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenalenylene group, a phenanthrenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a naphthacenylene group, a picenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a rubicenylene group, a coronenylene group, an ovalenylene group, a pyrrolylene group, a thiophenylene group, a furanylene group, a silolylene group, an imidazolylene group, a pyrazolylene group, a thiazolylene group, an isothiazolylene group, an oxazolylene group, an isoxazolylene group, a pyridinylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, an indolylene group, an isoindolylene group, an indazolylene group, a purinylene group, a quinolinylene group, an isoquinolinylene group, a benzoquinolinylene group, a phthalazinylene group, a naphthyridinylene group, a quinoxalinylene group, a quinazolinylene group, a cinnolinylene group, a phenanthridinylene group, an acridinylene group, a phenanthrolinylene group, a phenazinylene group, a benzimidazolylene group, a benzofuranylene group, a benzothiophenylene group, a benzosilolylene group, an isobenzothiazolylene group, a benzoxazolylene group, an isobenzoxazolylene group, a triazolylene group, a tetrazolylene group, an oxadiazolylene group, a triazinylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a dibenzosilolylene group, a carbazolylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a thiadiazolylene group, an imidazopyridinylene group, an imidazopyrimidinylene group, an oxazolopyridinylene group, a thiazolopyridinylene group, a benzonaphthyridinylene group, an azafluorenylene group, an azaspiro-bifluorenylene group, an azacarbazolylene group, an azadibenzofuranylene group, an azadibenzothiophenylene group, and an azadibenzosilolylene group; and a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, a heptalenylene group, an indacenylene group, an acenaphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a spiro-benzofluorene-fluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenalenylene group, a phenanthrenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a naphthacenylene group, a picenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a rubicenylene group, a coronenylene group, an ovalenylene group, a pyrrolylene group, a thiophenylene group, a furanylene group, a silolylene group, an imidazolylene group, a pyrazolylene group, a thiazolylene group, an isothiazolylene group, an oxazolylene group, an isoxazolylene group, a pyridinylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, an indolylene group, an isoindolylene group, an indazolylene group, a purinylene group, a quinolinylene group, an isoquinolinylene group, a benzoquinolinylene group, a phthalazinylene group, a naphthyridinylene group, a quinoxalinylene group, a quinazolinylene group, a cinnolinylene group, a phenanthridinylene group, an acridinylene group, a phenanthrolinylene group, a phenazinylene group, a benzimidazolylene group, a benzofuranylene group, a benzothiophenylene group, a benzosilolylene group, an isobenzothiazolylene group, a benzoxazolylene group, an isobenzoxazolylene group, a triazolylene group, a tetrazolylene group, an oxadiazolylene group, a triazinylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a dibenzosilolylene group, a carbazolylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a thiadiazolylene group, an imidazopyridinylene group, an imidazopyrimidinylene group, an oxazolopyridinylene group, a thiazolopyridinylene group, a benzonaphthyridinylene group, an azafluorenylene group, an azaspiro-bifluorenylene group, an azacarbazolylene group, an azadibenzofuranylene group, an azadibenzothiophenylene group, and an azadibenzosilolylene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, a terphenyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), wherein Q₃₁ to Q₃₃ are each independently selected from the group consisting of: a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, and a quinazolinyl group; and a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, and a quinazolinyl group, each substituted with at least one selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, and a phenyl group.
 6. The organic light-emitting device of claim 1, wherein R₁ to R₅, R₁₁, and R₁₂ are each independently selected from the group consisting of: hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group; a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, and a hydrazono group; a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a spiro-benzofluorene-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an oxazolopyridinyl group, a thiazolopyridinyl group, a benzonaphthyridinyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, an azadibenzosilolyl group, a benzofuranopyrimidinyl group, a benzothiophenopyrimidyl group, a pyrimidinoquinoxalinyl group, and an azaindenopyridinyl group; and a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a spiro-benzofluorene-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an oxazolopyridinyl group, a thiazolopyridinyl group, a benzonaphthyridinyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, an azadibenzosilolyl group, a benzofuranopyrimidinyl group, a benzothiophenopyrimidyl group, a pyrimidinoquinoxalinyl group, and an azaindenopyridinyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, a terphenyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), provided that R₁ to R₅, R₁₁, and R₁₂ are each independently not substituted with an anthracenyl group; wherein Q₃₁ to Q₃₃ are each independently selected from the group consisting of: a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, and a quinazolinyl group; and a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, and a quinazolinyl group, each substituted with at least one selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, and a phenyl group.
 7. The organic light-emitting device of claim 1, wherein R₂₇ and R₂₈ are each independently selected from the group consisting of: a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a spiro-benzofluorene-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an oxazolopyridinyl group, a thiazolopyridinyl group, a benzonaphthyridinyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, and an azadibenzosilolyl group; and a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a spiro-benzofluorene-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an oxazolopyridinyl group, a thiazolopyridinyl group, a benzonaphthyridinyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, and an azadibenzosilolyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, a terphenyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and wherein Q₁ to Q₃ and Q₃₁ to Q₃₃ are each independently selected from the group consisting of: a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, and a quinazolinyl group; and a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, and a quinazolinyl group, each substituted with at least one selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, and a phenyl group.
 8. The organic light-emitting device of claim 1, wherein the first compound is represented by one selected from Formulae 1A(1) to 1A(11), 1B(1), 1B(2), 1C(1) to 1C(4), 1D(1), and 1D(2):


9. The organic light-emitting device of claim 1, wherein the hole transport region comprises an emission auxiliary layer, the emission auxiliary layer directly contacts the emission layer, and the second compound is comprised in the emission auxiliary layer.
 10. The organic light-emitting device of claim 1, wherein the electron transport region comprises a buffer layer, the buffer layer directly contacts the emission layer, and the second compound is comprised in the buffer layer.
 11. The organic light-emitting device of claim 1, wherein the electron transport region comprises a buffer layer, an electron transport layer, and an electron injection layer, and the first compound is comprised in the electron transport layer.
 12. The organic light-emitting device of claim 11, wherein the electron transport layer comprises an alkaline metal, an alkaline earth metal, a rare-earth metal, an alkaline metal compound, an alkaline earth-metal compound, a rare-earth metal compound, an alkaline metal complex, an alkaline earth-metal complex, a rare-earth metal complex, or a combination thereof.
 13. The organic light-emitting device of claim 11, wherein the electron injection layer comprises an alkaline metal, an alkaline earth metal, a rare-earth metal, an alkaline metal compound, an alkaline earth-metal compound, a rare-earth metal compound, an alkaline metal complex, an alkaline earth-metal complex, a rare-earth metal complex, or a combination thereof.
 14. The organic light-emitting device of claim 13, wherein the electron injection layer comprises Li, Na, K, Rb, Cs, Mg, Ca, Er, Tm, Yb, or a combination thereof.
 15. The organic light-emitting device of claim 1, wherein the hole transport region comprises a p-dopant, and a lowest unoccupied molecular orbital (LUMO) of the p-dopant is about −3.5 eV or less.
 16. The organic light-emitting device of claim 15, wherein the p-dopant comprises a cyano group-containing compound.
 17. The organic light-emitting device of claim 1, wherein the emission layer is a first-color-light emission layer, and the organic light-emitting device further comprises, between the first electrode and the second electrode, i) at least one second-color-light emission layer or ii) at least one second-color-light emission layer and at least one third-color-light emission layer, wherein a maximum emission wavelength of the first-color-light emission layer, a maximum emission wavelength of the second-color-light emission layer, and a maximum emission wavelength of the third-color-light emission layer are identical to or different from one another, and when the organic light-emitting device operates, mixed light comprising first-color-light and second-color-light, or mixed light comprising first-color-light, second-color-light, and third-color-light is emitted.
 18. An organic light-emitting device comprising: a first electrode; a second electrode facing the first electrode; an emission layer between the first electrode and the second electrode; a hole transport region between the first electrode and the emission layer; and an electron transport region between the emission layer and the second electrode, wherein the electron transport region comprises a first compound, at least one selected from the hole transport region and the electron transport region comprises a second compound, the first compound is represented by one selected from Formulae 1A to 1D, and the second compound is represented by Formula 2A or Formula 2B:

wherein, in Formulae 1A to 1D, 2A, and 2B, ring A₁ is a C₅-C₆₀ carbocyclic group or a C₁-C₃₀ heterocyclic group, each substituted with at least one *-[(L₁₁)_(a11)-(R₁₁)_(b11)], and ring A₂ is a C₅-C₆₀ carbocyclic group or a C₁-C₃₀ heterocyclic group, each substituted with at least one *-[(L₁₂)_(a12)-(R₁₂)_(b12)], rings A₂₁, A₂₂, and A₂₃ are each independently a C₅-C₆₀ carbocyclic group or a C₁-C₃₀ heterocyclic group, each substituted with at least one *-[(L₂₂)_(a22)-(R₂₂)_(b22)], wherein at least one of rings A₂₁ and A₂₃ is selected from groups represented by Formulae 2-1 to 2-3, 2-8 to 2-17, and 2-24 to 2-36, each substituted with at least one *-[(L₂₂)_(a22)-(R₂₂)_(b22)]; or ring A₂₂ is selected from groups represented by Formulae 2-1 to 2-3, 2-12 to 2-28, and 2-33 to 2-36, each substituted with at least one *-[(L₂₂)_(a22)-(R₂₂)_(b22)]:

wherein, in Formulae 2-1 to 2-3 and 2-8 to 2-36, X₂₂ and X₂₃ are each independently O, S, or Se, or are each independently a moiety comprising C, N, or Si, T₂₁ to T₂₈ are each independently N, or are each independently a moiety comprising C, T₁ to T₄ are each independently carbon or nitrogen, wherein a bond between T₁ and T₂ is a single bond, and a bond between T₃ and T₄ is a double bond, ring A₁ is condensed with a 5-membered ring in Formulae 1B and 1D, while sharing T₁ and T₂ therewith, and ring A₂ is condensed with a 5-membered ring in Formulae 1C and 1D, while sharing T₃ and T₄ therewith, T₁₁ and T₁₂ are each independently carbon or nitrogen, T₁₃ is N or C(R₂₇), and T₁₄ is N or C(R₂₈), wherein two or more selected from three T₁₁(s) in Formula 2A are identical to or different from each other, two or more selected from three T₁₂(s) in Formula 2A are identical to or different from each other, two T₁₁(s) in Formula 2B are identical to or different from each other, two T₁₂(s) in Formula 2B are identical to or different from each other, T₁₁ and T₁₂ fused to ring A₂₂ of Formula 2A are both carbon, a bond between T₁₁ and T₁₂ is a single bond or a double bond, a case where three T₁₁(s) and three T₁₂(s) in Formula 2A are all nitrogen is excluded, and a case where two T₁₁(s), two T₁₂(s), T₁₃, and T₁₄ in Formula 2B are all nitrogen is excluded, rings A₂₁, A₂₂, and A₂₃ are each condensed with a 7-membered ring in each of Formulae 2A and 2B, while sharing T₁₁ and T₁₂ therewith, X₁ is selected from O, S, and N-[(L₁)_(a1)-(R₁)_(b1)], X₂ is N or C-(L₂)_(a2)-(R₂)_(b2), X₃ is N or C-(L₃)_(a3)-(R₃)_(b3), X₄ is N or C-(L₄)_(a4)-(R₄)_(b4), and X₅ is N or C-(L₅)_(a5)-(R₅)_(c5), X₂₁ is selected from O, S, Se, C(R₂₃)(R₂₄), Si(R₂₃)(R₂₄), and N-[(L₂₁)_(a21)-(R₂₁)_(b21)], L₁ to L₅, L₁₁, L₁₂, L₂₁, and L₂₂ are each independently selected from a substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀ arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group, a1 to a5, a11, a12, a21, and a22 are each independently an integer selected from 0 to 5, R₁ to R₅, R₁₁, R₁₂, R₂₁ to R₂₄, R₂₇, and R₂₈ are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂), b1 to b5, b11, b12, b21, and b22 are each independently an integer selected from 0 to 4, R₄ and R₅ are optionally connected to each other to form a saturated or unsaturated ring, and at least one substituent of the substituted C₃-C₁₀ cycloalkylene group, the substituted C₁-C₁₀ heterocycloalkylene group, the substituted C₃-C₁₀ cycloalkenylene group, the substituted C₁-C₁₀ heterocycloalkenylene group, the substituted C₆-C₆₀ arylene group, the substituted C₁-C₆₀ heteroarylene group, the substituted divalent non-aromatic condensed polycyclic group, the substituted divalent non-aromatic condensed heteropolycyclic group, the substituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group is selected from the group consisting of: deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group; a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂); a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, and a terphenyl group; a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂); and —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), wherein Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryl group substituted with a C₁-C₆₀ alkyl group, a C₆-C₆₀ aryl group substituted with a C₆-C₆₀ aryl group, a terphenyl group, a C₁-C₆₀ heteroaryl group, a C₁-C₆₀ heteroaryl group substituted with a C₁-C₆₀ alkyl group, a C₁-C₆₀ heteroaryl group substituted with a C₆-C₆₀ aryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group. 